First Case Report of Prader-Willi-Like Syndrome in Colombia (original) (raw)
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Prader–Willi syndrome: clinical genetics, cytogenetics and molecular biology
Expert Reviews in Molecular Medicine, 2005
Prader-Willi syndrome (PWS) is a neurodevelopmental disorder that arises from lack of expression of paternally inherited genes known to be imprinted and located in the chromosome 15q11-q13 region. PWS is considered the most common syndromal cause of life-threatening obesity and is estimated at 1 in 10,000 to 20,000 individuals. A de novo paternally derived chromosome 15q11-q13 deletion is the cause of PWS in about 70% of cases, and maternal disomy 15 accounts for about 25% of cases. The remaining cases of PWS result either from genomic imprinting defects (microdeletions or epimutations) of the imprinting centre in the 15q11-q13 region or from chromosome 15 translocations. Here, we describe the clinical presentation of PWS, review the current understanding of causative cytogenetic and molecular genetic mechanisms, and discuss future directions for research.
Clinical Genetics, 2004
Prader–Willi syndrome (PWS) can result from a 15q11–q13 paternal deletion, maternal uniparental disomy (UPD), or imprinting mutations. We describe here the phenotypic variability detected in 51 patients with different types of deletions and 24 patients with UPD. Although no statistically significant differences could be demonstrated between the two main types of PWS deletion patients, it was observed that type I (BP1-BP3) patients acquired speech later than type II (BP2-BP3) patients. Comparing the clinical pictures of our patients with UPD with those with deletions, we found that UPD children presented with lower birth length and started walking earlier and deletion patients presented with a much higher incidence of seizures than UPD patients. In addition, the mean maternal age in the UPD group was higher than in the deletion group. No statistically significant differences could be demonstrated between the deletion and the UPD group with respect to any of the major features of PWS. In conclusion, our study did not detect significant phenotypic differences among type I and type II PWS deletion patients, but it did demonstrate that seizures were six times more common in patients with a deletion than in those with UPD.
Prader-Willi Syndrome: Genetic Tests and Clinical Findings
Genetic Testing, 2000
Here we describe the genetic studies performed in 53 patients with the suspected diagnosis of Prader-Willi syndrome (PWS). PWS is characterized by neonatal hypotonia, hypogonadism, delayed psychomotor development, hyperphagia, obesity, short stature, small hands and feet, learning disabilities, and obsessive-compulsive behavior. Through the methylation analysis of the SNRPN gene, microsatellite studies of loci mapped within and outside the PWS/AS region, and fluorescence in situ hybridization (FISH) study, we confirmed the diagnosis in 35 patients: 27 with a paternal deletion, and 8 with maternal uniparental disomy (UPD). The clinical comparisons between deleted and UPD patients indicated that there were no major phenotype differences, except for a lower birth length observed in the UPD children. Our sample was composed of more girls than boys; UPD patients were diagnosed earlier than the deleted cohort (2 10/12 vs. 7 9/12 years); and, in the deleted group, the boys were diagnosed earlier than the girls (5 2/12 vs. 7 8/12 years, respectively).
Prader-Willi Syndrome - Clinical Genetics, Diagnosis and Treatment Approaches: An Update
Current Pediatric Reviews
Background: Prader-Willi Syndrome (PWS) is a neurodevelopmental genomic imprinting disorder with lack of expression of genes inherited from the paternal chromosome 15q11-q13 region usually from paternal 15q11-q13 deletions (about 60%) or maternal uniparental disomy 15 or both 15s from the mother (about 35%). An imprinting center controls the expression of imprinted genes in the chromosome 15q11-q13 region. Key findings include infantile hypotonia, a poor suck, failure to thrive and hypogonadism/hypogenitalism. Short stature and small hands/feet due to growth and other hormone deficiencies, hyperphagia and marked obesity occur in early childhood, if uncontrolled. Cognitive and behavioral problems (tantrums, compulsions, compulsive skin picking) are common. Objective: Hyperphagia and obesity with related complications are major causes of morbidity and mortality in PWS. This report will describe an accurate diagnosis with determination of specific genetic subtypes, appropriate medical ...
Prader Willi Syndrome: Phenotypic and Genotypic Characteristics
Prader-Willi Syndrome (PWS) is a genetic disease caused by a lack of the fatherly PWS/AS region of chromosome 15. Its prevalence is estimated at 1 in 20,000 to 25,000 births. We report the cases of 15 patients followed at the department of endocrinology. The diagnosis of PWS was based on clinical criteria of HOLMS and al and genetic study. The sex ratio B/G was 8/7. Average age was 8.2 years (3-17).The reason for consultation was short stature: 2/3 associated with obesity 7/10. In other cases, children consulted for isolated obesity. Clinical presentation was typical in the majority of cases. All the major criteria for the diagnosis were found in patients with the exception of hypogonadism who was present in 2/3. Genetically, 8 patients have benefited from a genetic study. This was 2 Xq27-qter duplications, 5 deletions: 3p26.3 (n:1), 1p36 (n=1), p21.1 (n:1), q11.2 (n=2) of paternal chromosome 15 and one maternal disomy.
An interstitial 15q11-q14 deletion: Expanded Prader-Willi syndrome phenotype
American Journal of Medical Genetics Part A, 2010
We present an infant girl with a de novo interstitial deletion of the chromosome 15q11-q14 region, larger than the typical deletion seen in Prader-Willi syndrome (PWS). She presented with features seen in PWS including hypotonia, a poor suck, feeding problems and mild micrognathia. She also presented with features not typically seen in PWS such as preauricular ear tags, a high arched palate, edematous feet, coarctation of the aorta, a PDA and a bicuspid aortic valve. G-banded chromosome analysis showed a large de novo deletion of the proximal long arm of chromosome 15 confirmed using FISH probes (D15511 and GABRB3). Methylation testing was abnormal and consistent with the diagnosis of PWS. Because of the large appearing deletion by karyotype analysis, an array comparative genomic hybridization (CGH) was performed. A 12.3 Mb deletion was found which involved the 15q11-q14 region containing approximately 60 protein coding genes. This rare deletion was approximately twice the size of the typical deletion seen in PWS and involved the proximal breakpoint BP1 and the distal breakpoint was located in the 15q14 band between previously recognized breakpoints BP5 and BP6. The deletion extended slightly distal to the AVEN gene including the neighboring CHRM5 gene. There is no evidence that the genes in the 15q14 band are imprinted; therefore, their potential contribution in this patient's expanded Prader-Willi syndrome phenotype must be a consequence of dosage sensitivity of the genes or due to altered expression of intact neighboring genes from a position effect.
Changing rates of genetic subtypes of Prader–Willi syndrome in the UK
European Journal of Human Genetics, 2007
The genetically determined neurodevelopmental disorder, Prader-Willi syndrome (PWS), has two main genetic subtypes: a 15q11-q13 deletion affecting the paternally inherited chromosome 15 and chromosome 15 maternal uniparental disomy (mUPD) in which two maternal copies of chromosome 15 are inherited but no paternal copy. It has been accepted that these subtypes occur in approximately 70 and 25% of cases, respectively. This is the first report of a greater proportion (50%) of those with PWS due to mUPD in children presently under 5 years living in the UK. Increasing maternal age at conception is likely to explain the changing proportions in this generation of mothers.