Deborah Wenkert - Academia.edu (original) (raw)

Papers by Deborah Wenkert

Research paper thumbnail of Evaluating The Effect Of Food, Fasting And Exercise On Inorganic Pyrophosphate (PPi) Levels In Healthy Subjects

Research paper thumbnail of Long-Term Sequelae of Bisphosph onate-Induced Osteopetrosis: Metaphyseal Osteopenia, Osteosclerosis Fragility, and No vel Bone Modeling Defects After Drug Administration Ceases

FIGURE 6: A) Computed tomography of the patient’s knees in 2007, here showing the distal femur (T... more FIGURE 6: A) Computed tomography of the patient’s knees in 2007, here showing the distal femur (Top), revealed widened metaphyses with thin cortices and a paucity of trabecular bone (arrow), compared to healthy boys of similar age (Bottom). In both distal femoral metaphyses there is expanded bone with a remarkable, large, central area (arrow) featuring a paucity of trabecular bone. B) Coronal sectioning of the CT shows the modeling defects and metaphyseal osteopenia and a vertical pattern of trabeculae. The subarticular epiphyseal bone is inexplicably dense (arrow). ABSTRACT

Research paper thumbnail of Hypophosphatasia: Vitamin B6 status of affected children and adults

Bone, 2021

Hypophosphatasia (HPP) is the heritable dento-osseous disease caused by loss-of-function mutation... more Hypophosphatasia (HPP) is the heritable dento-osseous disease caused by loss-of-function mutation(s) of the gene ALPL that encodes the tissue-nonspecific isoenzyme of alkaline phosphatase (TNSALP). TNSALP is a cell-surface homodimeric phosphomonoester phosphohydrolase expressed in healthy people especially in the skeleton, liver, kidneys, and developing teeth. In HPP, diminished TNSALP activity leads to extracellular accumulation of its natural substrates including inorganic pyrophosphate (PPi), an inhibitor of mineralization, and pyridoxal 5'-phosphate (PLP), the principal circulating form of vitamin B6 (B6). Autosomal dominant and autosomal recessive inheritance involving >450 usually missense defects scattered throughout ALPL largely explains the remarkably broad-ranging severity of this inborn-error-of-metabolism. In 1985 when we identified elevated plasma PLP as a biochemical hallmark of HPP, all 14 investigated affected children and adults had markedly increased PLP levels. However, pyridoxal (PL), the dephosphorylated form of PLP that enters cells to cofactor many enzymatic reactions, was not low but often inexplicably elevated. Levels of pyridoxic acid (PA), the B6 degradation product quantified to assess B6 sufficiency, were unremarkable. Canonical signs or symptoms of B6 deficiency or toxicity were absent. B6-dependent seizures in infants with life-threatening HPP were later explained by their profound deficiency of TNSALP activity blocking PLP dephosphorylation to PL and diminishing gamma-hydroxybutyric acid synthesis in the brain. Now, there is speculation that altered B6 metabolism causes further clinical complications in HPP. Herein, we assessed the plasma PL and PA levels accompanying previously reported elevated plasma PLP concentrations in 150 children and adolescents with HPP. Their mean (SD) plasma PL level was nearly double the mean for our healthy pediatric controls: 66.7 (59.0) nM versus 37.1 (22.2) nM (P < 0.0001), respectively. Their PA levels were broader than our pediatric control range, but their mean value was normal; 40.2 (25.1) nM versus 39.3 (9.9) nM (P = 0.7793), respectively. In contrast, adults with HPP often had plasma PL and PA levels suggestive of dietary B6 insufficiency. We discuss why the B6 levels of our pediatric patients with HPP would not cause B6 toxicity or deficiency, whereas in affected adults dietary B6 insufficiency can develop.

Research paper thumbnail of Non-endemic skeletal fluorosis: Causes and associated secondary hyperparathyroidism (case report and literature review)

Bone, 2021

Skeletal fluorosis (SF) is endemic primarily in regions with fluoride (F)-contaminated well water... more Skeletal fluorosis (SF) is endemic primarily in regions with fluoride (F)-contaminated well water, but can reflect other types of chronic F exposure. Calcium (Ca) and vitamin D (D) deficiency can exacerbate SF. A 51-year-old man with years of musculoskeletal pain and opiate use was hypocalcemic with secondary hyperparathyroidism upon manifesting recurrent long bone fractures. He smoked cigarettes, drank large amounts of cola beverage, and consumed little dietary Ca. Then, after 5 months of Ca and D 3 supplementation, serum 25(OH)D was 21 ng/mL (Nl, 30-100), corrected serum Ca had normalized from 7.8 to 9.4 mg/dL (Nl, 8.5-10.1), alkaline phosphatase (ALP) had decreased from 1080 to 539 U/L (Nl, 46-116), yet parathyroid hormone (PTH) had increased from 133 to 327 pg/mL (Nl, 8.7-77.1). Radiographs revealed generalized osteosclerosis and a cystic osteopenic area in the left femoral neck and intertrochanteric region. DXA BMD Z-scores were +7.4 and +0.4 at the lumbar spine and "1/3" radius, respectively. Bone

Research paper thumbnail of Hyperphosphatemia with low FGF7 and normal FGF23 and sFRP4 levels in the circulation characterizes pediatric hypophosphatasia

Bone, 2020

Hypophosphatasia (HPP) is the inborn-error-of-metabolism caused by loss-of-function mutation(s) o... more Hypophosphatasia (HPP) is the inborn-error-of-metabolism caused by loss-of-function mutation(s) of the ALPL gene that encodes the tissue-nonspecific isoenzyme of alkaline phosphatase (TNSALP). TNSALP in healthy individuals is on cell surfaces richly in bone, liver, and kidney. Thus, TNSALP natural substrates accumulate extracellularly in HPP, including inorganic pyrophosphate (PPi), a potent inhibitor of hydroxyapatite crystal formation and growth. Superabundance of extracellular PPi (ePPi) in HPP impairs mineralization of bones and teeth, often leading to rickets during childhood and osteomalacia in adult life and to tooth loss at any age. HPP's remarkably broad-ranging severity is largely explained by nearly four hundred typically missense mutations throughout the ALPL gene that are transmitted as an autosomal dominant or autosomal recessive trait. In the clinical laboratory, the biochemical hallmark of HPP is low serum ALP activity (hypophosphatasemia). However, our experience indicates that hyperphosphatemia from increased renal reclamation of filtered inorganic phosphate (Pi) is also common.

Research paper thumbnail of X‐Linked Hypophosphatemia: Uniquely Mild Disease Associated With PHEX 3′‐UTR Mutation c.*231A>G (A Retrospective Case–Control Study)

Journal of Bone and Mineral Research, 2020

PSS designed the case-control study, collected data by chart review, and drafted the manuscript. ... more PSS designed the case-control study, collected data by chart review, and drafted the manuscript. GSG, FC, BR, DW, and VW carried out the diagnosis, treatment, and clinical characterization of the study participants. VW identified the age/sex-matched subjects comprising the two study groups. MH and SM performed and interpreted the PHEX mutation analyses. FZ directed, performed, and guided the interpretation of the statistical analyses and created the tables and figures. MPW organized the patient and family studies and finalized the revised manuscript.

Research paper thumbnail of Bruck syndrome 2 variant lacking congenital contractures and involving a novel compound heterozygous PLOD2 mutation

Bone, 2019

Bruck syndrome (BRKS) is the rare disorder that features congenital joint contractures often with... more Bruck syndrome (BRKS) is the rare disorder that features congenital joint contractures often with pterygia and subsequent fractures, early on called osteogenesis imperfecta (OI) type XI (OMIM # 610968). Its two forms, BRKS1 (OMIM # 259450) and BRKS2 (OMIM # 609220), reflect autosomal recessive (AR) inheritance of FKBP10 and PLOD2 loss-of-function mutations, respectively. A 10-year-old girl was referred with blue sclera, osteopenia, poorly-healing fragility fractures, Wormian skull bones, cleft soft palate, congenital fusion of cervical vertebrae, progressive scoliosis, bell-shaped thorax, restrictive and reactive pulmonary disease, protrusio acetabuli, short stature, and additional dysmorphic features without joint contractures. Iliac crest biopsy after alendronate treatment that improved her bone density revealed low trabecular

Research paper thumbnail of Hypophosphatasia: Natural history study of 101 affected children investigated at one research center

Bone, Dec 26, 2016

Hypophosphatasia (HPP) is the inborn-error-of-metabolism that features deficient activity of the ... more Hypophosphatasia (HPP) is the inborn-error-of-metabolism that features deficient activity of the tissue-nonspecific isoenzyme of alkaline phosphatase (TNSALP). Resultant extracellular accumulation of inorganic pyrophosphate, a TNSALP substrate and potent inhibitor of mineralization, typically leads to tooth loss and sometimes to rickets or osteomalacia. HPP's remarkably broad-ranging severity is largely explained by autosomal dominant versus autosomal recessive transmission from among several hundred usually missense mutations positioned throughout the gene that encodes TNSALP. In 2015, our cross-sectional investigation of 173 affected children validated and expanded the clinical nosology commonly used for pediatric HPP. Herein, for the 101 patients in that cohort with longitudinal data, we explored the natural history of pediatric HPP by assessing their z-scores for height and then for weight, grip strength, and bone mineral density (BMD) determined by dual energy X-ray absorpt...

Research paper thumbnail of Congenital insensitivity to pain: Fracturing without apparent skeletal pathobiology caused by an autosomal dominant, second mutation in SCN11A encoding voltage-gated sodium channel 1.9

Bone, Jan 31, 2015

Congenital insensitivity to pain (CIP) comprises the rare heritable disorders without peripheral ... more Congenital insensitivity to pain (CIP) comprises the rare heritable disorders without peripheral neuropathy that feature inability to feel pain. Fracturing and joint destruction are common complications, but lack detailed studies of mineral and skeletal homeostasis and bone histology. In 2013, discovery of a heterozygous gain-of-function mutation in SCN11A encoding voltage-gated sodium channel 1.9 (Nav1.9) established a distinctive CIP in three unrelated patients who suffered multiple painless fractures, self-inflicted mutilation, chronic diarrhea, and hyperhidrosis. Here, we studied a mother and two children with CIP by physical examination, biochemical testing, radiological imaging including DXA, iliac crest histology, and mutation analysis. She suffered fractures primarily of her lower extremities beginning at age two years, and had Charcot deformity of both ankles and joint hypermobility. Nerve conduction velocity and biopsy and electromyography were normal. Her children had rec...

Research paper thumbnail of Auricular ossification: A newly recognized feature of osteoprotegerin-deficiency juvenile Paget disease

American journal of medical genetics. Part A, Jan 14, 2016

We report auricular ossification (AO) affecting the elastic cartilage of the ear as a newly recog... more We report auricular ossification (AO) affecting the elastic cartilage of the ear as a newly recognized feature of osteoprotegerin (OPG)-deficiency juvenile Paget disease (JPD). AO and auricular calcification refer interchangeably to rigid pinnae, sparing the ear lobe, from various etiologies. JPD is a rare Mendelian disorder characterized by elevated serum alkaline phosphatase activity accompanied by skeletal pain and deformity from rapid bone turnover. Autosomal recessive transmission of loss-of-function mutations within TNFRSF11B encoding OPG accounts for most JPD (JPD1). JPD2 results from heterozygous constitutive activation of TNFRSF11A encoding RANK. Other causes of JPD remain unknown. In 2007, we reported a 60-year-old man with JPD1 who described hardening of his external ears at age 45 years, after 4 years of treatment with bisphosphonates (BPs). Subsequently, we noted rigid pinnae in a 17-year-old boy and 14-year-old girl, yet pliable pinnae in a 12-year-old boy, each with J...

Research paper thumbnail of Hypophosphatasia: Natural History of 177 Pediatric Patients

Research paper thumbnail of Primary Disorders of Bone and Connective Tissues

Textbook of Pediatric Rheumatology, 2011

Research paper thumbnail of Timing ofthe Appearance ofMacron uclear-specific Histone Varianthv1 and Gene Expression inDeveloping New Macronuclei ofTetrahymenathermophila

Research paper thumbnail of Herpes zoster reactivation in patients with rheumatoid arthritis: Analysis of disease characteristics and disease modifying anti-rheumatic drugs

Arthritis care & research, Jan 27, 2015

Identify rheumatoid arthritis (RA) characteristics associated with increased herpes zoster (HZ) r... more Identify rheumatoid arthritis (RA) characteristics associated with increased herpes zoster (HZ) risk in Corrona registry RA patients. Evaluate the risk in initiators of TNF-α inhibitors (TNFi), or non-TNF-α inhibitor biologics (nTNFi) or (among those who were currently on or had been previously treated with methotrexate) conventional synthetic disease-modifying antirheumatic drugs (csDMARDs) other than methotrexate. Cox regression modeling estimated the association between first HZ incidence and selected RA characteristics including disease activity. Medication-related risk for HZ in RA patients on current or past methotrexate (to exclude milder RA disease) were categorized by treatment initiation (TNFi, vs nTNFi, vs csDMARD). Hazard ratios (HR) estimated HZ risk of each treatment-initiation category after stratification on trimmed propensity score (PS) quintiles to control for potential confounders. 28,852 patients contributed 95,287 person-years. 729 observed HZ cases yielded a 7....

Research paper thumbnail of AB0472 The frequency of methotrexate (MTX) or prednisone discontinuation and of TNF inhibitor (TNFI) discontinuation/switching in rheumatoid arthritis (RA) patients results from 2002-2004 and 2007-2009 in a large us registry

Annals of the Rheumatic Diseases, 2013

ABSTRACT Background A greater percentage of RA patients respond to combination therapy with metho... more ABSTRACT Background A greater percentage of RA patients respond to combination therapy with methotrexate (MTX) and a TNFi, than respond to either agent by itself. However, the discontinuation (DC) or withdrawal of MTX, corticosteroids (CS) or biologic agents such as TNFi after prolonged periods of combination treatment, if successful, should benefit RA patients by decreasing expense and exposure to potential side effects. Objectives To evaluate the frequency of withdrawal of combination treatment within 3 years of initiation by experienced US rheumatologists and whether these practice patterns had changed between ’02-’04 and ’07-’09. Methods We compared the recorded incidence of discontinuation of prednisone, and of combined therapy with MTX and TNFi among RA patients (who newly initiatied combination therapy) with at least 3 years of follow-up enrolled in the CORRONA US registry for the periods ’02-’04 and ’07-’09. We further examined the disease activity during these different periods by CDAI measurement. Infliximab data was not included as its combined use with MTX is mandated. Pts DC’ing a TNFi include those switched to a different TNFi. For the ’07-’09 group, some data was available documenting reason for change including: lack of efficacy, toxicity, formulary restriction, pt preference, infection, lack of insurance, and physician preference. Results 239 patients with 3 yrs of follow-up, initiated combination therapy in ’02-’04 compared with 97 in ’07-’09. Age and gender were balanced. In the period ’02-’04 vs. ’07-’09, 63.2% vs. 54.6% of patients had CDAI &gt;10 (Moderate disease) with means of 18.4 and 14.4 respectively (NS). Most patients added TNFi to MTX (63.2% ’02-’04 vs. 71.1% ’07-’09, NS). Of those RA patients on combination therapy with TNFi and MTX, in ’02-’04 vs. ’07-’09: 65% vs. 71% stopped MTX and or TNFi; 10.9% vs. 13.4% DC’d MTX only, 33.9% vs. 40.2% discontinued or switched TNFi only and 20.1% vs. 17.5% discontinued both. All comparisons were not significant. Lack of insurance and formulary restriction were recorded as reason for discontinued only in the “discontinued both” group. Of patients on either TNFi and/or MTX in combination with prednisone, in the period ’02-’04 vs. ’07-’09, 26.8% vs. 35.1% of patients stopped prednisone, this was not statistically significant. Conclusions Discontinuation/switching of MTX, prednisone and TNFi occurred frequently in the 3 yrs after the initiation of combination therapy. There were no statistical differences in the rate of discontinuation of either MTX or prednisone; or discontinuation/switching of TNFi in the period 2002-2004 vs 2007-2009. Disease activity, by CDAI, trended lower in patients with RA initiating combination therapy in the ’07-’09 period, but discontinuation/switching of TNFi trended higher during this time. Dose tapering rates, without discontinuation, will be reported as will discontinuation vs. switch of a TNFi. Disclosure of Interest J. Kremer Shareholder of: CORRONA, Grant/Research support from: Abbott, Amgen, AstraZeneca, BMS, Genentech, Lilly, Consultant for: Amgen, Genentech, Lilly, Pfizer, Employee of: CORRONA, Speakers Bureau: Abbott, Amgen, BMS, Pfizer, D. Wenkert Shareholder of: Amgen, Employee of: Amgen, S. Grant: None Declared, P. Xu: None Declared, A. Koenig Shareholder of: Pfizer, Employee of: Pfizer, D. Collier Shareholder of: Amgen, Employee of: Amgen

Research paper thumbnail of Multicentric carpotarsal osteolysis syndrome is caused by only a few domain-specific mutations in MAFB, a negative regulator of RANKL-induced osteoclastogenesis

American journal of medical genetics. Part A, 2014

Multicentric carpotarsal osteolysis syndrome (MCTO), an autosomal dominant disorder that often pr... more Multicentric carpotarsal osteolysis syndrome (MCTO), an autosomal dominant disorder that often presents sporadically, features carpal-tarsal lysis frequently followed by nephropathy and renal failure. In 2012, mutations in the single-exon gene MAFB were reported in 13 probands with MCTO. MAFB is a negative regulator of RANKL-mediated osteoclastogenesis. We studied nine MCTO patients (seven sporadic patients and one affected mother and son) for MAFB mutation. We PCR-amplified and selectively sequenced the MAFB region that contains the transactivation domain in this 323 amino acid protein, where mutations were previously reported for MCTO. We found five different heterozygous missense defects among eight probands: c.176C > T, p.Pro59Leu; c.185C > T, p.Thr62Ile; c.206C > T, p.Ser69Leu (four had this defect); c.209C > T, p.Ser70Leu; and c.211C > T, p.Pro71Ser. All 5 mutations are within a 13 amino acid stretch of the transactivation domain. Four were identical to the prev...

Research paper thumbnail of Hypophosphatasia: Validation and expansion of the clinical nosology for children from 25years experience with 173 pediatric patients

Bone, 2015

Hypophosphatasia (HPP) is caused by loss-of-function mutation(s) within the gene TNSALP that enco... more Hypophosphatasia (HPP) is caused by loss-of-function mutation(s) within the gene TNSALP that encodes the &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot;tissue-nonspecific&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot; isoenzyme of alkaline phosphatase (TNSALP).In HPP, inorganic pyrophosphate, an inhibitor of mineralization and substrate for TNSALP, accumulates extracellularly often leading to rickets or osteomalacia and tooth loss, and sometimes to craniosynostosis and calcium crystal arthropathies. HPP&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;s remarkably broad-ranging expressivity spans stillbirth from profound skeletal hypomineralization to adult-onset dental problems or arthropathies without bone disease, which is largely explained by autosomal recessive versus autosomal dominant transmission from among several hundred, usually missense, TNSALP mutations. For clinical purposes, this expressivity has been codified according to absence or presence of skeletal disease and then patient age at presentation and diagnosis. Pediatric patients are reported principally with…

Research paper thumbnail of PHEX3′-UTR c.*231A>G Near The Polyadenylation Signal Is a Relatively Common, Mild, American Mutation That Masquerades as Sporadic or X-Linked Recessive Hypophosphatemic Rickets

Journal of Bone and Mineral Research, 2014

Heritable forms of hypophosphatemic rickets (HR) include X-linked dominant (XLH), autosomal reces... more Heritable forms of hypophosphatemic rickets (HR) include X-linked dominant (XLH), autosomal recessive, and autosomal dominant HR (from deactivating mutations in PHEX, DMP1 or ENPP1, and activating mutations in FGF23, respectively). Over 30 years, we have cared for 284 children with HR. For those 72 deemed sporadic XLH, we preliminarily reported mutation analysis for 30 subjects. Eleven had PHEX mutations. However, the remaining 19 lacked readily identifiable defects in PHEX, DMP1, or FGF23. In 2008, a novel single-base change near the polyadenylation (pA) signal in the 3&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;-UTR of PHEX was identified in XLH by other investigators. This c.*231A &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt; G mutation is 3-bp upstream of the putative pA signal (AATAAA) in PHEX. Accordingly, we investigated whether this 3&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;-UTR defect accounted for HR in any of these 19 sporadic XLH patients. PCR amplification and sequencing of their…

Research paper thumbnail of Timing of the appearance of macronuclear-specific histone variant hv1 and gene expression in developing new macronuclei of Tetrahymena thermophila

Journal of Cell Biology, 1984

Vegetative cells of the ciliated protozoan Tetrahymena thermophila contain a transcriptionally ac... more Vegetative cells of the ciliated protozoan Tetrahymena thermophila contain a transcriptionally active macronucleus and a transcriptionally inactive micronucleus. Earlier studies ( Allis , C. D., C. V. C. Glover , J. K. Bowen, and M. A. Gorovsky , 1980, Cell, 20:609-617; and Allis , C. D., Y. S. Ziegler , M. A. Gorovsky , and J. B. Olmsted, 1982, Cell, 31:131-136) demonstrated the existence of a macronuclear-specific histone variant, hv1 , which is enriched in small punctate regions in nucleoli of several mammalian cell lines. These observations suggest that this histone variant is highly conserved in evolution and may be associated with actively transcribed sequences. Despite large differences in structure and function during vegetative growth, macro- and micronuclei are related. During conjugation, the sexual phase of the life cycle in Tetrahymena, postzygotic division products of micronuclei give rise to new micro- and macronuclei, while the old macronucleus moves to the posterior...

Research paper thumbnail of Malignancies in children and young adults on etanercept: summary of cases from clinical trials and post marketing reports

Pediatric Rheumatology, 2013

Background: Malignancy risk may be increased in chronic inflammatory conditions that are mediated... more Background: Malignancy risk may be increased in chronic inflammatory conditions that are mediated by tumor necrosis factor (TNF), such as juvenile idiopathic arthritis (JIA), but the role of TNF in human cancer biology is unclear. In response to a 2011 United States Food & Drug Administration requirement of TNF blocker manufacturers, we evaluated reporting rates of all malignancies in patients ≤30 years old who received the TNF blocker etanercept. Methods: All malignancies in etanercept-exposed patients aged ≤30 years from the Amgen clinical trial database (CTD) and postmarketing global safety database (PMD) were reviewed. PMD reporting rates were generated using exposure information based on commercial sources. Age-specific incidence rates of malignancy for the general US population were generated from the Surveillance Epidemiology and End Results (SEER) database v7.0.9. Results: There were 2 malignancies in the CTD: 1 each in etanercept and placebo/comparator arms (both in patients 18-30 years old). Postmarketing etanercept exposure was 231,404 patient-years (62,379 patient-years in patients 0-17 years; 168,485 patient-years in patients 18-30 years). Reporting rates of malignancy per 100,000 patient-years in the PMD and incidence rates in SEER were 32.0 and 15.9, respectively, for patients 0-17 years and 46.9 and 42.1 for patients 18-30 years old. Reporting rates were higher than SEER incidence rates for Hodgkin lymphoma in the 0-17 years age group. PMD reporting rates per 100,000 patient-years and SEER incidence rates per 100,000 person-years for Hodgkin lymphoma were 9.54 and 0.9, respectively, for patients 0-17 years and 1.8 and 4.2 for patients 18-30 years old. There were ≥5 cases of leukemia, lymphoma, melanoma, thyroid, and cervical cancers. Leukemia, non-Hodgkin lymphoma, melanoma, thyroid cancer, and cervical cancer rates were similar in the PMD and SEER. Conclusions: Overall PMD malignancy reporting rates in etanercept-treated patients 0-17 years appeared higher than incidence rates in SEER, attributable to rates of Hodgkin lymphoma. Comparison to patients with similar burden of disease cannot be made; JIA, particularly very active disease, may be a risk factor for lymphoma. No increased malignancy reporting rate in the PMD relative to SEER was observed in the young-adult age group.

Research paper thumbnail of Evaluating The Effect Of Food, Fasting And Exercise On Inorganic Pyrophosphate (PPi) Levels In Healthy Subjects

Research paper thumbnail of Long-Term Sequelae of Bisphosph onate-Induced Osteopetrosis: Metaphyseal Osteopenia, Osteosclerosis Fragility, and No vel Bone Modeling Defects After Drug Administration Ceases

FIGURE 6: A) Computed tomography of the patient’s knees in 2007, here showing the distal femur (T... more FIGURE 6: A) Computed tomography of the patient’s knees in 2007, here showing the distal femur (Top), revealed widened metaphyses with thin cortices and a paucity of trabecular bone (arrow), compared to healthy boys of similar age (Bottom). In both distal femoral metaphyses there is expanded bone with a remarkable, large, central area (arrow) featuring a paucity of trabecular bone. B) Coronal sectioning of the CT shows the modeling defects and metaphyseal osteopenia and a vertical pattern of trabeculae. The subarticular epiphyseal bone is inexplicably dense (arrow). ABSTRACT

Research paper thumbnail of Hypophosphatasia: Vitamin B6 status of affected children and adults

Bone, 2021

Hypophosphatasia (HPP) is the heritable dento-osseous disease caused by loss-of-function mutation... more Hypophosphatasia (HPP) is the heritable dento-osseous disease caused by loss-of-function mutation(s) of the gene ALPL that encodes the tissue-nonspecific isoenzyme of alkaline phosphatase (TNSALP). TNSALP is a cell-surface homodimeric phosphomonoester phosphohydrolase expressed in healthy people especially in the skeleton, liver, kidneys, and developing teeth. In HPP, diminished TNSALP activity leads to extracellular accumulation of its natural substrates including inorganic pyrophosphate (PPi), an inhibitor of mineralization, and pyridoxal 5'-phosphate (PLP), the principal circulating form of vitamin B6 (B6). Autosomal dominant and autosomal recessive inheritance involving >450 usually missense defects scattered throughout ALPL largely explains the remarkably broad-ranging severity of this inborn-error-of-metabolism. In 1985 when we identified elevated plasma PLP as a biochemical hallmark of HPP, all 14 investigated affected children and adults had markedly increased PLP levels. However, pyridoxal (PL), the dephosphorylated form of PLP that enters cells to cofactor many enzymatic reactions, was not low but often inexplicably elevated. Levels of pyridoxic acid (PA), the B6 degradation product quantified to assess B6 sufficiency, were unremarkable. Canonical signs or symptoms of B6 deficiency or toxicity were absent. B6-dependent seizures in infants with life-threatening HPP were later explained by their profound deficiency of TNSALP activity blocking PLP dephosphorylation to PL and diminishing gamma-hydroxybutyric acid synthesis in the brain. Now, there is speculation that altered B6 metabolism causes further clinical complications in HPP. Herein, we assessed the plasma PL and PA levels accompanying previously reported elevated plasma PLP concentrations in 150 children and adolescents with HPP. Their mean (SD) plasma PL level was nearly double the mean for our healthy pediatric controls: 66.7 (59.0) nM versus 37.1 (22.2) nM (P < 0.0001), respectively. Their PA levels were broader than our pediatric control range, but their mean value was normal; 40.2 (25.1) nM versus 39.3 (9.9) nM (P = 0.7793), respectively. In contrast, adults with HPP often had plasma PL and PA levels suggestive of dietary B6 insufficiency. We discuss why the B6 levels of our pediatric patients with HPP would not cause B6 toxicity or deficiency, whereas in affected adults dietary B6 insufficiency can develop.

Research paper thumbnail of Non-endemic skeletal fluorosis: Causes and associated secondary hyperparathyroidism (case report and literature review)

Bone, 2021

Skeletal fluorosis (SF) is endemic primarily in regions with fluoride (F)-contaminated well water... more Skeletal fluorosis (SF) is endemic primarily in regions with fluoride (F)-contaminated well water, but can reflect other types of chronic F exposure. Calcium (Ca) and vitamin D (D) deficiency can exacerbate SF. A 51-year-old man with years of musculoskeletal pain and opiate use was hypocalcemic with secondary hyperparathyroidism upon manifesting recurrent long bone fractures. He smoked cigarettes, drank large amounts of cola beverage, and consumed little dietary Ca. Then, after 5 months of Ca and D 3 supplementation, serum 25(OH)D was 21 ng/mL (Nl, 30-100), corrected serum Ca had normalized from 7.8 to 9.4 mg/dL (Nl, 8.5-10.1), alkaline phosphatase (ALP) had decreased from 1080 to 539 U/L (Nl, 46-116), yet parathyroid hormone (PTH) had increased from 133 to 327 pg/mL (Nl, 8.7-77.1). Radiographs revealed generalized osteosclerosis and a cystic osteopenic area in the left femoral neck and intertrochanteric region. DXA BMD Z-scores were +7.4 and +0.4 at the lumbar spine and "1/3" radius, respectively. Bone

Research paper thumbnail of Hyperphosphatemia with low FGF7 and normal FGF23 and sFRP4 levels in the circulation characterizes pediatric hypophosphatasia

Bone, 2020

Hypophosphatasia (HPP) is the inborn-error-of-metabolism caused by loss-of-function mutation(s) o... more Hypophosphatasia (HPP) is the inborn-error-of-metabolism caused by loss-of-function mutation(s) of the ALPL gene that encodes the tissue-nonspecific isoenzyme of alkaline phosphatase (TNSALP). TNSALP in healthy individuals is on cell surfaces richly in bone, liver, and kidney. Thus, TNSALP natural substrates accumulate extracellularly in HPP, including inorganic pyrophosphate (PPi), a potent inhibitor of hydroxyapatite crystal formation and growth. Superabundance of extracellular PPi (ePPi) in HPP impairs mineralization of bones and teeth, often leading to rickets during childhood and osteomalacia in adult life and to tooth loss at any age. HPP's remarkably broad-ranging severity is largely explained by nearly four hundred typically missense mutations throughout the ALPL gene that are transmitted as an autosomal dominant or autosomal recessive trait. In the clinical laboratory, the biochemical hallmark of HPP is low serum ALP activity (hypophosphatasemia). However, our experience indicates that hyperphosphatemia from increased renal reclamation of filtered inorganic phosphate (Pi) is also common.

Research paper thumbnail of X‐Linked Hypophosphatemia: Uniquely Mild Disease Associated With PHEX 3′‐UTR Mutation c.*231A>G (A Retrospective Case–Control Study)

Journal of Bone and Mineral Research, 2020

PSS designed the case-control study, collected data by chart review, and drafted the manuscript. ... more PSS designed the case-control study, collected data by chart review, and drafted the manuscript. GSG, FC, BR, DW, and VW carried out the diagnosis, treatment, and clinical characterization of the study participants. VW identified the age/sex-matched subjects comprising the two study groups. MH and SM performed and interpreted the PHEX mutation analyses. FZ directed, performed, and guided the interpretation of the statistical analyses and created the tables and figures. MPW organized the patient and family studies and finalized the revised manuscript.

Research paper thumbnail of Bruck syndrome 2 variant lacking congenital contractures and involving a novel compound heterozygous PLOD2 mutation

Bone, 2019

Bruck syndrome (BRKS) is the rare disorder that features congenital joint contractures often with... more Bruck syndrome (BRKS) is the rare disorder that features congenital joint contractures often with pterygia and subsequent fractures, early on called osteogenesis imperfecta (OI) type XI (OMIM # 610968). Its two forms, BRKS1 (OMIM # 259450) and BRKS2 (OMIM # 609220), reflect autosomal recessive (AR) inheritance of FKBP10 and PLOD2 loss-of-function mutations, respectively. A 10-year-old girl was referred with blue sclera, osteopenia, poorly-healing fragility fractures, Wormian skull bones, cleft soft palate, congenital fusion of cervical vertebrae, progressive scoliosis, bell-shaped thorax, restrictive and reactive pulmonary disease, protrusio acetabuli, short stature, and additional dysmorphic features without joint contractures. Iliac crest biopsy after alendronate treatment that improved her bone density revealed low trabecular

Research paper thumbnail of Hypophosphatasia: Natural history study of 101 affected children investigated at one research center

Bone, Dec 26, 2016

Hypophosphatasia (HPP) is the inborn-error-of-metabolism that features deficient activity of the ... more Hypophosphatasia (HPP) is the inborn-error-of-metabolism that features deficient activity of the tissue-nonspecific isoenzyme of alkaline phosphatase (TNSALP). Resultant extracellular accumulation of inorganic pyrophosphate, a TNSALP substrate and potent inhibitor of mineralization, typically leads to tooth loss and sometimes to rickets or osteomalacia. HPP's remarkably broad-ranging severity is largely explained by autosomal dominant versus autosomal recessive transmission from among several hundred usually missense mutations positioned throughout the gene that encodes TNSALP. In 2015, our cross-sectional investigation of 173 affected children validated and expanded the clinical nosology commonly used for pediatric HPP. Herein, for the 101 patients in that cohort with longitudinal data, we explored the natural history of pediatric HPP by assessing their z-scores for height and then for weight, grip strength, and bone mineral density (BMD) determined by dual energy X-ray absorpt...

Research paper thumbnail of Congenital insensitivity to pain: Fracturing without apparent skeletal pathobiology caused by an autosomal dominant, second mutation in SCN11A encoding voltage-gated sodium channel 1.9

Bone, Jan 31, 2015

Congenital insensitivity to pain (CIP) comprises the rare heritable disorders without peripheral ... more Congenital insensitivity to pain (CIP) comprises the rare heritable disorders without peripheral neuropathy that feature inability to feel pain. Fracturing and joint destruction are common complications, but lack detailed studies of mineral and skeletal homeostasis and bone histology. In 2013, discovery of a heterozygous gain-of-function mutation in SCN11A encoding voltage-gated sodium channel 1.9 (Nav1.9) established a distinctive CIP in three unrelated patients who suffered multiple painless fractures, self-inflicted mutilation, chronic diarrhea, and hyperhidrosis. Here, we studied a mother and two children with CIP by physical examination, biochemical testing, radiological imaging including DXA, iliac crest histology, and mutation analysis. She suffered fractures primarily of her lower extremities beginning at age two years, and had Charcot deformity of both ankles and joint hypermobility. Nerve conduction velocity and biopsy and electromyography were normal. Her children had rec...

Research paper thumbnail of Auricular ossification: A newly recognized feature of osteoprotegerin-deficiency juvenile Paget disease

American journal of medical genetics. Part A, Jan 14, 2016

We report auricular ossification (AO) affecting the elastic cartilage of the ear as a newly recog... more We report auricular ossification (AO) affecting the elastic cartilage of the ear as a newly recognized feature of osteoprotegerin (OPG)-deficiency juvenile Paget disease (JPD). AO and auricular calcification refer interchangeably to rigid pinnae, sparing the ear lobe, from various etiologies. JPD is a rare Mendelian disorder characterized by elevated serum alkaline phosphatase activity accompanied by skeletal pain and deformity from rapid bone turnover. Autosomal recessive transmission of loss-of-function mutations within TNFRSF11B encoding OPG accounts for most JPD (JPD1). JPD2 results from heterozygous constitutive activation of TNFRSF11A encoding RANK. Other causes of JPD remain unknown. In 2007, we reported a 60-year-old man with JPD1 who described hardening of his external ears at age 45 years, after 4 years of treatment with bisphosphonates (BPs). Subsequently, we noted rigid pinnae in a 17-year-old boy and 14-year-old girl, yet pliable pinnae in a 12-year-old boy, each with J...

Research paper thumbnail of Hypophosphatasia: Natural History of 177 Pediatric Patients

Research paper thumbnail of Primary Disorders of Bone and Connective Tissues

Textbook of Pediatric Rheumatology, 2011

Research paper thumbnail of Timing ofthe Appearance ofMacron uclear-specific Histone Varianthv1 and Gene Expression inDeveloping New Macronuclei ofTetrahymenathermophila

Research paper thumbnail of Herpes zoster reactivation in patients with rheumatoid arthritis: Analysis of disease characteristics and disease modifying anti-rheumatic drugs

Arthritis care & research, Jan 27, 2015

Identify rheumatoid arthritis (RA) characteristics associated with increased herpes zoster (HZ) r... more Identify rheumatoid arthritis (RA) characteristics associated with increased herpes zoster (HZ) risk in Corrona registry RA patients. Evaluate the risk in initiators of TNF-α inhibitors (TNFi), or non-TNF-α inhibitor biologics (nTNFi) or (among those who were currently on or had been previously treated with methotrexate) conventional synthetic disease-modifying antirheumatic drugs (csDMARDs) other than methotrexate. Cox regression modeling estimated the association between first HZ incidence and selected RA characteristics including disease activity. Medication-related risk for HZ in RA patients on current or past methotrexate (to exclude milder RA disease) were categorized by treatment initiation (TNFi, vs nTNFi, vs csDMARD). Hazard ratios (HR) estimated HZ risk of each treatment-initiation category after stratification on trimmed propensity score (PS) quintiles to control for potential confounders. 28,852 patients contributed 95,287 person-years. 729 observed HZ cases yielded a 7....

Research paper thumbnail of AB0472 The frequency of methotrexate (MTX) or prednisone discontinuation and of TNF inhibitor (TNFI) discontinuation/switching in rheumatoid arthritis (RA) patients results from 2002-2004 and 2007-2009 in a large us registry

Annals of the Rheumatic Diseases, 2013

ABSTRACT Background A greater percentage of RA patients respond to combination therapy with metho... more ABSTRACT Background A greater percentage of RA patients respond to combination therapy with methotrexate (MTX) and a TNFi, than respond to either agent by itself. However, the discontinuation (DC) or withdrawal of MTX, corticosteroids (CS) or biologic agents such as TNFi after prolonged periods of combination treatment, if successful, should benefit RA patients by decreasing expense and exposure to potential side effects. Objectives To evaluate the frequency of withdrawal of combination treatment within 3 years of initiation by experienced US rheumatologists and whether these practice patterns had changed between ’02-’04 and ’07-’09. Methods We compared the recorded incidence of discontinuation of prednisone, and of combined therapy with MTX and TNFi among RA patients (who newly initiatied combination therapy) with at least 3 years of follow-up enrolled in the CORRONA US registry for the periods ’02-’04 and ’07-’09. We further examined the disease activity during these different periods by CDAI measurement. Infliximab data was not included as its combined use with MTX is mandated. Pts DC’ing a TNFi include those switched to a different TNFi. For the ’07-’09 group, some data was available documenting reason for change including: lack of efficacy, toxicity, formulary restriction, pt preference, infection, lack of insurance, and physician preference. Results 239 patients with 3 yrs of follow-up, initiated combination therapy in ’02-’04 compared with 97 in ’07-’09. Age and gender were balanced. In the period ’02-’04 vs. ’07-’09, 63.2% vs. 54.6% of patients had CDAI &gt;10 (Moderate disease) with means of 18.4 and 14.4 respectively (NS). Most patients added TNFi to MTX (63.2% ’02-’04 vs. 71.1% ’07-’09, NS). Of those RA patients on combination therapy with TNFi and MTX, in ’02-’04 vs. ’07-’09: 65% vs. 71% stopped MTX and or TNFi; 10.9% vs. 13.4% DC’d MTX only, 33.9% vs. 40.2% discontinued or switched TNFi only and 20.1% vs. 17.5% discontinued both. All comparisons were not significant. Lack of insurance and formulary restriction were recorded as reason for discontinued only in the “discontinued both” group. Of patients on either TNFi and/or MTX in combination with prednisone, in the period ’02-’04 vs. ’07-’09, 26.8% vs. 35.1% of patients stopped prednisone, this was not statistically significant. Conclusions Discontinuation/switching of MTX, prednisone and TNFi occurred frequently in the 3 yrs after the initiation of combination therapy. There were no statistical differences in the rate of discontinuation of either MTX or prednisone; or discontinuation/switching of TNFi in the period 2002-2004 vs 2007-2009. Disease activity, by CDAI, trended lower in patients with RA initiating combination therapy in the ’07-’09 period, but discontinuation/switching of TNFi trended higher during this time. Dose tapering rates, without discontinuation, will be reported as will discontinuation vs. switch of a TNFi. Disclosure of Interest J. Kremer Shareholder of: CORRONA, Grant/Research support from: Abbott, Amgen, AstraZeneca, BMS, Genentech, Lilly, Consultant for: Amgen, Genentech, Lilly, Pfizer, Employee of: CORRONA, Speakers Bureau: Abbott, Amgen, BMS, Pfizer, D. Wenkert Shareholder of: Amgen, Employee of: Amgen, S. Grant: None Declared, P. Xu: None Declared, A. Koenig Shareholder of: Pfizer, Employee of: Pfizer, D. Collier Shareholder of: Amgen, Employee of: Amgen

Research paper thumbnail of Multicentric carpotarsal osteolysis syndrome is caused by only a few domain-specific mutations in MAFB, a negative regulator of RANKL-induced osteoclastogenesis

American journal of medical genetics. Part A, 2014

Multicentric carpotarsal osteolysis syndrome (MCTO), an autosomal dominant disorder that often pr... more Multicentric carpotarsal osteolysis syndrome (MCTO), an autosomal dominant disorder that often presents sporadically, features carpal-tarsal lysis frequently followed by nephropathy and renal failure. In 2012, mutations in the single-exon gene MAFB were reported in 13 probands with MCTO. MAFB is a negative regulator of RANKL-mediated osteoclastogenesis. We studied nine MCTO patients (seven sporadic patients and one affected mother and son) for MAFB mutation. We PCR-amplified and selectively sequenced the MAFB region that contains the transactivation domain in this 323 amino acid protein, where mutations were previously reported for MCTO. We found five different heterozygous missense defects among eight probands: c.176C > T, p.Pro59Leu; c.185C > T, p.Thr62Ile; c.206C > T, p.Ser69Leu (four had this defect); c.209C > T, p.Ser70Leu; and c.211C > T, p.Pro71Ser. All 5 mutations are within a 13 amino acid stretch of the transactivation domain. Four were identical to the prev...

Research paper thumbnail of Hypophosphatasia: Validation and expansion of the clinical nosology for children from 25years experience with 173 pediatric patients

Bone, 2015

Hypophosphatasia (HPP) is caused by loss-of-function mutation(s) within the gene TNSALP that enco... more Hypophosphatasia (HPP) is caused by loss-of-function mutation(s) within the gene TNSALP that encodes the &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot;tissue-nonspecific&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot; isoenzyme of alkaline phosphatase (TNSALP).In HPP, inorganic pyrophosphate, an inhibitor of mineralization and substrate for TNSALP, accumulates extracellularly often leading to rickets or osteomalacia and tooth loss, and sometimes to craniosynostosis and calcium crystal arthropathies. HPP&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;s remarkably broad-ranging expressivity spans stillbirth from profound skeletal hypomineralization to adult-onset dental problems or arthropathies without bone disease, which is largely explained by autosomal recessive versus autosomal dominant transmission from among several hundred, usually missense, TNSALP mutations. For clinical purposes, this expressivity has been codified according to absence or presence of skeletal disease and then patient age at presentation and diagnosis. Pediatric patients are reported principally with…

Research paper thumbnail of PHEX3′-UTR c.*231A>G Near The Polyadenylation Signal Is a Relatively Common, Mild, American Mutation That Masquerades as Sporadic or X-Linked Recessive Hypophosphatemic Rickets

Journal of Bone and Mineral Research, 2014

Heritable forms of hypophosphatemic rickets (HR) include X-linked dominant (XLH), autosomal reces... more Heritable forms of hypophosphatemic rickets (HR) include X-linked dominant (XLH), autosomal recessive, and autosomal dominant HR (from deactivating mutations in PHEX, DMP1 or ENPP1, and activating mutations in FGF23, respectively). Over 30 years, we have cared for 284 children with HR. For those 72 deemed sporadic XLH, we preliminarily reported mutation analysis for 30 subjects. Eleven had PHEX mutations. However, the remaining 19 lacked readily identifiable defects in PHEX, DMP1, or FGF23. In 2008, a novel single-base change near the polyadenylation (pA) signal in the 3&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;-UTR of PHEX was identified in XLH by other investigators. This c.*231A &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt; G mutation is 3-bp upstream of the putative pA signal (AATAAA) in PHEX. Accordingly, we investigated whether this 3&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;-UTR defect accounted for HR in any of these 19 sporadic XLH patients. PCR amplification and sequencing of their…

Research paper thumbnail of Timing of the appearance of macronuclear-specific histone variant hv1 and gene expression in developing new macronuclei of Tetrahymena thermophila

Journal of Cell Biology, 1984

Vegetative cells of the ciliated protozoan Tetrahymena thermophila contain a transcriptionally ac... more Vegetative cells of the ciliated protozoan Tetrahymena thermophila contain a transcriptionally active macronucleus and a transcriptionally inactive micronucleus. Earlier studies ( Allis , C. D., C. V. C. Glover , J. K. Bowen, and M. A. Gorovsky , 1980, Cell, 20:609-617; and Allis , C. D., Y. S. Ziegler , M. A. Gorovsky , and J. B. Olmsted, 1982, Cell, 31:131-136) demonstrated the existence of a macronuclear-specific histone variant, hv1 , which is enriched in small punctate regions in nucleoli of several mammalian cell lines. These observations suggest that this histone variant is highly conserved in evolution and may be associated with actively transcribed sequences. Despite large differences in structure and function during vegetative growth, macro- and micronuclei are related. During conjugation, the sexual phase of the life cycle in Tetrahymena, postzygotic division products of micronuclei give rise to new micro- and macronuclei, while the old macronucleus moves to the posterior...

Research paper thumbnail of Malignancies in children and young adults on etanercept: summary of cases from clinical trials and post marketing reports

Pediatric Rheumatology, 2013

Background: Malignancy risk may be increased in chronic inflammatory conditions that are mediated... more Background: Malignancy risk may be increased in chronic inflammatory conditions that are mediated by tumor necrosis factor (TNF), such as juvenile idiopathic arthritis (JIA), but the role of TNF in human cancer biology is unclear. In response to a 2011 United States Food & Drug Administration requirement of TNF blocker manufacturers, we evaluated reporting rates of all malignancies in patients ≤30 years old who received the TNF blocker etanercept. Methods: All malignancies in etanercept-exposed patients aged ≤30 years from the Amgen clinical trial database (CTD) and postmarketing global safety database (PMD) were reviewed. PMD reporting rates were generated using exposure information based on commercial sources. Age-specific incidence rates of malignancy for the general US population were generated from the Surveillance Epidemiology and End Results (SEER) database v7.0.9. Results: There were 2 malignancies in the CTD: 1 each in etanercept and placebo/comparator arms (both in patients 18-30 years old). Postmarketing etanercept exposure was 231,404 patient-years (62,379 patient-years in patients 0-17 years; 168,485 patient-years in patients 18-30 years). Reporting rates of malignancy per 100,000 patient-years in the PMD and incidence rates in SEER were 32.0 and 15.9, respectively, for patients 0-17 years and 46.9 and 42.1 for patients 18-30 years old. Reporting rates were higher than SEER incidence rates for Hodgkin lymphoma in the 0-17 years age group. PMD reporting rates per 100,000 patient-years and SEER incidence rates per 100,000 person-years for Hodgkin lymphoma were 9.54 and 0.9, respectively, for patients 0-17 years and 1.8 and 4.2 for patients 18-30 years old. There were ≥5 cases of leukemia, lymphoma, melanoma, thyroid, and cervical cancers. Leukemia, non-Hodgkin lymphoma, melanoma, thyroid cancer, and cervical cancer rates were similar in the PMD and SEER. Conclusions: Overall PMD malignancy reporting rates in etanercept-treated patients 0-17 years appeared higher than incidence rates in SEER, attributable to rates of Hodgkin lymphoma. Comparison to patients with similar burden of disease cannot be made; JIA, particularly very active disease, may be a risk factor for lymphoma. No increased malignancy reporting rate in the PMD relative to SEER was observed in the young-adult age group.