J Korean Pediatr Soc.  2002 Sep;45(9):1126-1133.

Clinical Characteristics and Genetic Analysis of Prader-Willi Syndrome

• Lee JE
• Moon KB
• Hwang JH
• Kwon EK
• Kim SH
• Kim JW
• Jin DK

Abstract

PURPOSE: Prader-Willi syndrome(PWS) is a complex disorder affecting multisystems with characteristic clinical features. Its genetic basis is an expression defect in the paternally derived chromosome 15q11-q13. We analyzed the clinical features and genetic basis of PWS patients for early detection and treatment.
METHODS
We retrospectively studied 24 patients with PWS in Department of Pediatrics, Samsung Medical Center, from September 1997 to September 2001. We performed cytogenetic and molecular genetic techniques using high resolution GTG banding techniques, fluorescent in situ hybridization and methylation-specific PCR for CpG island of SNRPN gene region.
RESULTS
The average birth weight of PWS patients was 2.67+/-0.47 kg and median age at diagnosis was 1.3 years. The average height and weight of PWS patients under one year at diagnostic time were located in a 3-10 percentile relatively, and a rapid weight gain was seen between two and six years. Feeding problems in infancy and neonatal hypotonia were the two most consistently positive major criteria in over 95% of the patients. In 18 of the 24 cases(75%), deletion of chromosome 15q11-q13 was demonstrated and one case among 18 had an unbalanced 14;15 translocation. In four cases without any cytogenetic abnormality, it may be considered as maternal uniparental disomy and the rest showed another findings.
CONCLUSION
We suggest diagnostic testing for PWS in all infants/neonates with unexplained feeding problems and hypotonia. It is necessary for clinically suspicious patients to undergo an early genetic test. As the genetic basis of PWS was heterogenous and complex, further study is required.

Keyword

Prader-Willi syndrome; Clinical feature; Genetic analysis

MeSH Terms

Birth Weight
Chromosome Aberrations
CpG Islands
Cytogenetics
Diagnosis
Diagnostic Tests, Routine
Humans
In Situ Hybridization, Fluorescence
Molecular Biology
Muscle Hypotonia
Pediatrics
Polymerase Chain Reaction
Prader-Willi Syndrome*
Retrospective Studies
snRNP Core Proteins
Uniparental Disomy
Weight Gain
snRNP Core Proteins