title: FISH detection of chromosome 15 deletions in Prader-Willi and Angelman syndromes.
abstract: We have evaluated fluorescence in situ hybridization (FISH) analysis for the clinical laboratory detection of the 15q11-q13 deletion seen in Prader-Willi syndrome (PWS) and Angelman syndrome (AS) using probes for loci D15S11, SNRPN, D15S10, and GABRB3. In a series of 118 samples from patients referred for PWS or AS, 29 had deletions by FISH analysis. These included two brothers with a paternally transmitted deletion detectable with the probe for SNRPN only. G-banding analysis was less sensitive for deletion detection but useful in demonstrating other cytogenetic alterations in four cases. Methylation and CA-repeat analyses of 15q11-q13 were used to validate the FISH results. Clinical findings of patients with deletions were variable, ranging from newborns with hypotonia as the only presenting feature to children who were classically affected. We conclude that FISH analysis is a rapid and reliable method for detection of deletions within 15q11-q13 and whenever a deletion is found, FISH analysis of parental chromosomes should also be considered.
authors.affiliation: Department of Pediatrics, Hospital for Sick Children, Toronto, Ontario, Canada.
authors.forename: I
authors.initials: I
authors.lastname: Teshima
authors.forename: D
authors.initials: D
authors.lastname: Chadwick
authors.forename: D
authors.initials: D
authors.lastname: Chitayat
authors.forename: J
authors.initials: J
authors.lastname: Kobayashi
authors.forename: P
authors.initials: P
authors.lastname: Ray
authors.forename: C
authors.initials: C
authors.lastname: Shuman
authors.forename: J
authors.initials: J
authors.lastname: Siegel-Bartelt
authors.forename: P
authors.initials: P
authors.lastname: Strasberg
authors.forename: R
authors.initials: R
authors.lastname: Weksberg
mesh_terms: D017204:Angelman Syndrome / Q000235:genetics*; D002871:Chromosome Banding; D002872:Chromosome Deletion; D002884:Chromosomes, Human, Pair 15; D018900:Dinucleotide Repeats; D005260:Female; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D008297:Male; D008745:Methylation; D011218:Prader-Willi Syndrome / Q000235:genetics*