Molecular cytogenetic detection of chromosome 15 deletions in patients with Prader-Willi and Angelman syndromes
- Hospital for Sick Children, Toronto (Canada); and others
Prader-Willi syndrome (PWS) and Angelman syndrome (AS) are clinically distinct genetic disorders involving alterations of chromosome 15q11-q13. Approximately 75% of individuals with PWS and AS have deletions within 15q11-q13 by molecular analysis. We have evaluated fluorescence in situ hybridization (FISH) for the clinical laboratory detection of del(15)(q11q13) using the cosmid probes D15S11 and GABRB3 (ONCOR, Gaithersburg, NY). 4/4 PWS and 1/1 AS patients previously identified as having cytogenetic deletions were deleted for both probes. In a prospectively ascertained series of 54 patient samples referred to rule out either PWS or AS, 8 were deleted for D15S11 and GABRB3. In addition, an atypical deletion patient with PWS was also identified who was found to be deleted for GABRB3 but not D15S11. The SNRPN locus was also deleted in this patient. Only 4 of the 9 patient samples having molecular cytogenetic deletions were clearly deleted by high resolution banding (HRB) analysis. The microscopic and submicroscopic deletions have been confirmed by dinucleotide (CA) repeat analysis. Microsatellite polymorphism analysis was also used to demonstrate that five non-deletion patients in this series had biparental inheritance of chromosome 15, including region q11-q13. Deletions were not detected by either HRB, FISH or microsatellite polymorphism analysis in samples obtained from parents of the deletion patients. Methylation studies of chromosome 15q11-q13 are in progress for this series of PWS and AS families. FISH analysis of chromosome 15q11-q13 in patients with PWS and AS is a rapid, sensitive and reliable method for deletion detection.
- OSTI ID:
- 133660
- Report Number(s):
- CONF-941009--
- Journal Information:
- American Journal of Human Genetics, Journal Name: American Journal of Human Genetics Journal Issue: Suppl.3 Vol. 55; ISSN AJHGAG; ISSN 0002-9297
- Country of Publication:
- United States
- Language:
- English
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