LEOPARD Syndrome: A Variant of Noonan Syndrome Strongly Associated With Hypertrophic Cardiomyopathy (original) (raw)
Mutations in the The Spectrum of Cardiac Anomalies in Noonan Syndrome as a Result of
2010
OBJECTIVE. Noonan syndrome is a clinically homogeneous but genetically heterogeneous condition. Type 1 Noonan syndrome is defined by the presence of a mutation in the PTPN11 gene, which is found in ϳ40% of the cases. Phenotype descriptions and cardiac defects from cohorts with Noonan syndrome were delineated in the "pregenomic era." We report the heart defects and links to gene dysfunction in cardiac development in a large cohort of patients with type 1 Noonan syndrome.
Genotype–phenotype analysis and natural history of left ventricular hypertrophy in LEOPARD syndrome
American Journal of Medical Genetics Part A, 2008
Because it is unclear whether the genotype may influence the clinical course in patients with LEOPARD syndrome (LS), we analyzed clinical and molecular predictors of adverse cardiac events in patients with left ventricular hypertrophy (LVH). A comprehensive cardiovascular evaluation, including baseline electrocardiogram, echocardiography, exercise test and 24 hr Holter monitoring at the time of clinical diagnosis and during follow-up was conducted on 24 patients referred to our departments. Phenotypical examination and diagnosis were performed by expert clinical geneticists. The entire PTPN11 and RAF1 coding regions were screened for mutations by DHPLC analysis, followed by sequencing. Patients without PTPN11 mutations (34%) showed a higher frequency of family history of sudden death (P ¼ 0.007), increased left atrial dimensions (P ¼ 0.05), bradyarrhythmias (P ¼ 0.04), episodes of supraventricular tachycardias (P ¼ 0.06), atrial fibrillation (P ¼ 0.009), and nonsustained ventricular tachycardias (P ¼ 0.05) during Holter monitoring. Six patients (25%) had adverse cardiac events during follow-up (including sudden deaths, resuscitated cardiac arrest, septal myectomy, and heart failure). LVH, New York Heart Association Class, left ventricular outflow tract obstruction, and nonsustained ventricular tachycardias were associated to adverse cardiac events. Of note, three patients with mutations in exon 13 showed a severe obstructive cardiomyopathy, with serious cardiac complications during follow-up (heart failure, septal myectomy, and sudden death). In conclusion, patients with LVH associated with LS seem to carry a relatively high risk of adverse (arrhythmic and nonarrhythmic) events. Further genotype-phenotype studies are warranted to fully elucidate the impact of the genotype on the natural history of patients with LS and LVH. ß
Survival Implications: Hypertrophic Cardiomyopathy in Noonan Syndrome
Congenital Heart Disease, 2011
Objectives. To understand relationships and survival implications between structural heart disease and hypertrophic cardiomyopathy in Noonan syndrome (Noonan syndrome-HCM), we reviewed the clinical course of 138 children with Noonan syndrome diagnosed with cardiovascular abnormalities and compared survival with the 30 children with Noonan syndrome-HCM with 120 contemporaneous children with nonsyndromic HCM. Methods. Study cohorts represent consecutive cases diagnosed at our institution 1966 through 2006. Outcomes were modeled using multiphase parametric techniques followed by multivariable regression with bagging. Results. Cardiac abnormalities in Noonan syndrome: Cardiac abnormalities in the 138 Noonan syndrome children included pulmonary valve dysplasia (52%), hypertrophic cardiomyopathy (22%), atrial septal defect (20%), ventricular septal defect (10%), mitral valve dysplasia (6%), coarctation (3%), and Fallot's tetralogy (2%). Need for surgery was high but not different from children with structural defects coexisting with HCM. Overall, late survival in children with Noonan syndrome and cardiac defects was good (91 Ϯ 3% at 15 years), although significantly worse for those with Noonan syndrome-HCM (P < .01). Noonan syndrome-HCM vs. nonsyndromic HCM: In the 30 children with Noonan syndrome-HCM, structural cardiac malformations coexisted in 18 (57%). The incidence of structural cardiac malformations in nonsyndromic HCM was instead 3/120 (2.5%, P < .001). Risk-adjusted late survival was significantly worse for Noonan syndrome-HCM than for nonsyndromic HCM (P = .02). Conclusions. Noonan syndrome-HCM frequently coexists with structural cardiac malformations, whereas nonsyndromic HCM does not; their natural histories may therefore be different. Late survival is significantly worse for Noonan syndrome-HCM than nonsyndromic HCM.
Biventricular Hypertrophic Cardiomyopathy in a Child with LEOPARD Syndrome: a Case Report
Journal of Interdisciplinary Medicine
Background:LEOPARD syndrome is a complex dysmorphogenetic disorder of inconstant penetrance and various morphologic expressions. The syndrome is an autosomal dominant disease that features multiple lentigines, electrocardiographic changes, eye hypertelorism, pulmonary valve stenosis or hypertrophic cardiomyopathy, genital malformations, and a delayed constitutional growth hearing loss, which can be associated with rapidly progressive severe biventricular obstructive hypertrophic cardiomyopathy. No epidemiologic data are available on the real incidence of LEOPARD syndrome; however, this seems to be a rare disease, being often underdiagnosed, as many of its features are mild.Case presentation:We report the case of a 10-year-old female pediatric patient, diagnosed with obstructive hypertrophic cardiomyopathy at the age of 3 months, and recently diagnosed with LEOPARD syndrome. The patient first presented for a cardiologic examination at the age of 3 months, due to a murmur. She present...
Genes
In this report, an atypical case of Noonan syndrome (NS) associated with sarcomeric hypertrophic cardiomyopathy (HCM) in a 33-year-old patient was described. Genetic testing revealed two different disease-causing mutations: a mutation in the PTPN11 gene, explaining NS, and a mutation in the MYBPC3 gene, known to be associated with HCM. This case exemplifies the challenge in achieving a definite etiological diagnosis in patients with HCM and the need to exclude other diseases mimicking this condition (genocopies or phenocopies). Compound heterozygous mutations are rare but possible in HCM patients. In conclusion, this study highlights the important role of genetic testing as a necessary diagnostic tool for performing a definitive etiological diagnosis of HCM.
Gain-of-function RAF1 mutations cause Noonan and LEOPARD syndromes with hypertrophic cardiomyopathy
Nature Genetics, 2007
Noonan and LEOPARD syndromes are developmental disorders with overlapping features, including cardiac abnormalities, short stature and facial dysmorphia. Increased RAS signaling owing to PTPN11, SOS1 and KRAS mutations causes B60% of Noonan syndrome cases 1-6 , and PTPN11 mutations cause 90% of LEOPARD syndrome cases 7 . Here, we report that 18 of 231 individuals with Noonan syndrome without known mutations (corresponding to 3% of all affected individuals) and two of six individuals with LEOPARD syndrome without PTPN11 mutations have missense mutations in RAF1, which encodes a serine-threonine kinase that activates MEK1 and MEK2. Most mutations altered a motif flanking Ser259, a residue critical for autoinhibition of RAF1 through 14-3-3 binding. Of 19 subjects with a RAF1 mutation in two hotspots, 18 (or 95%) showed hypertrophic cardiomyopathy (HCM), compared with the 18% prevalence of HCM among individuals with Noonan syndrome in general. Ectopically expressed RAF1 mutants from the two HCM hotspots had increased kinase activity and enhanced ERK activation, whereas non-HCM-associated mutants were kinase impaired. Our findings further implicate increased RAS signaling in pathological cardiomyocyte hypertrophy.
Cardiovascular disease in Noonan syndrome
Archives of Disease in Childhood, 2014
Background Noonan syndrome (NS), a relatively common autosomal dominant disorder with an incidence of 1 in 1000 to 2500 live births, is the most common syndromic cause of congenital heart disease after Trisomy 21. Objective To comprehensively define the spectrum of cardiac morphology and specific clinical course of a large cohort of NS patients. Design Retrospective, descriptive case series study. Patients An international Harvard-based NS registry was combined with clinical data from NS patients followed at Boston Children's Hospital, Massachusetts, USA. Results We identified 293 patients with NS. Cardiovascular disease was seen in 81% (n=237) including pulmonary stenosis in 57%, secundum atrial septal defects in 32% and hypertrophic cardiomyopathy in 16%. A genetic mutation of the RAS-MAPK signalling pathway was identified in 62% (n=136). Genotypephenotype associations were noted between PTPN11 mutations and atrial septal defects (p=0.001), and pulmonary stenosis (p<0.001). RAF1 mutations were associated with hypertrophic cardiomyopathy (p<0.001). Cardiovascular outcomes that differed specifically in a NS cohort included high re-intervention rates (65%) after percutaneous balloon pulmonary valvuloplasty for valvar pulmonary stenosis. Additionally, in NS patients with hypertrophic cardiomyopathy, a clinically significant regression of hypertrophy (17%) was observed as was a markedly higher incidence of concomitant congenital heart defects (70%). Conclusions Patients with NS have a distinct spectrum of cardiac phenotypes that may have a natural history and response to therapy atypical to that normally seen in non-syndromic heart disease. A diagnosis of NS in a patient with pulmonary stenosis or infant-onset hypertrophic cardiomyopathy would facilitate conditionspecific counselling on outcome and prognosis.
Klinische Wochenschrift, 1991
The case of a 50-year-old patient with hypertrophic obstructive cardiomyopathy is reported. The patient demonstrated somatic signs of the Turner phenotype, but a cytogenetically normal karyotype was shown. These findings were compatible with the diagnosis of Noonan syndrome. The most commonly diagnosed cardiac disease in this syndrome is pulmonary stenosis, followed by hypertrophic cardiomyopathy. The patient's prognosis is limited by the natural history or the typical complications of the underlying cardiac lesion.
Arrhythmogenic Cardiomyopathy in a Patient with Noonan Syndrome
Fetal & Pediatric Pathology, 2010
Arrhythmogenic ventricular cardiomyopathy (AVC) presents with fat replacement of the myocardium, most commonly of the right ventricle, and ventricular arrhythmias. We report an 11-yearold boy with Noonan syndrome, ventricular arrhythmias, and an ultrasound depicting hypertrophy of the ventricular septum with subaortic stenosis. A surgical resection of the left side of the ventricular septum revealed a thick fibroelastotic endocardium covering a broad band of mature adipose tissue focally containing myocardial cells, fibrosis and chronic inflammatory infiltrates. The two layers covered a band of hypertrophic myocardiocytes with mild interstitial fibrosis. Arrhythmogenic ventricular cardiomyopathy has not been previously reported in the Noonan syndrome.