Clinical and genetic analysis for four Chinese families with Prader-Willi syndrome.
Prader-Willi syndrome (PWS) is a complex, genetic, multisystem disorder. Its major clinical features include neonatal hypotonia and failure to thrive, mental retardation, hypogonadism, short hands and feet, hyperphagia-caused obesity, and characteristic appearance. The genetic basis of PWS is also complex. It is caused by the absence of expression of the active paternal genes such as the SNRPN, NDN, and possibly others in the PWS critical region on 15q11-13. PWS is in effect a contiguous gene syndrome resulting from deletion of the paternal copies of the imprinted. Consensus in clinical diagnostic criteria was established in 1993. However, identifying relevant patients for tests remains a challenge for most practitioners, as many features of the disorder are nonspecific, and others can be subtle or evolved over time. Consequently, molecular genetic tests can be used to diagnose PWS accurately, allowing early diagnosis of the syndrome. High resolution G-banding, high resolution cytogenetic methylation-specific PCR (MS-PCR), and fluorescence in situ hybridization (FISH) are routinely used to diagnose PWS. In this study, four Chinese patients, with typical PWS features, were detected by MS-PCR and FISH. Three were cytogenetically normal, but lacked paternal expression of proximal chromosome 15q because of maternal uniparental disomy (UPD). The other one, however, demonstrated an unbalanced de novo translocation 46, XX, t (7; 15).
Zhang
Yu-wen
YW
Department of Endocrine and Metabolic Diseases, Shanghai Institute of Endocrine and Metabolic Diseases, Shanghai Jiaotong University School of Medicine, Shanghai, 200025, People's Republic of China.
Jia
Hui-ying
HY
Hong
Jie
J
Ge
Yan
Y
Zhang
Hui-jie
HJ
Shen
Chun-fang
CF
Ye
Lei
L
Cui
Bin
B
Li
Xiao-ying
XY
Gu
Wei-qiong
WQ
Zhang
Yi-fei
YF
Wang
Wei-qing
WQ
Ning
Guang
G
D000293:Adolescent; D044466:Asian People / Q000235:genetics*; D002648:Child; D002884:Chromosomes, Human, Pair 15; D019175:DNA Methylation; D005192:Family Health; D005260:Female; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D008297:Male; D009767:Obesity, Morbid / Q000235:genetics / Q000473:pathology; D016133:Polymerase Chain Reaction; D011218:Prader-Willi Syndrome / Q000235:genetics* / Q000473:pathology; D014178:Translocation, Genetic; D055815:Young Adult