RT Journal Article
SR Electronic
T1 Molecular and cytogenetic studies of the Prader-Willi syndrome.
JF Journal of Medical Genetics
JO J Med Genet
FD BMJ Publishing Group Ltd
SP 649
OP 654
DO 10.1136/jmg.28.10.649
VO 28
IS 10
A1 R J Trent
A1 F Volpato
A1 A Smith
A1 R Lindeman
A1 M K Wong
A1 G Warne
A1 E Haan
YR 1991
UL http://jmg.bmj.com/content/28/10/649.abstract
AB Twenty-seven subjects with the Prader-Willi syndrome (PWS) were studied. Sixteen (59%) had a cytogenetic deletion involving chromosome 15q11-13. Nine were non-deletional and two patients had structural rearrangements of chromosome 15: 47,XY, + del(15)(pter----q12), var(15)(p11) and 45,XX,t(14q15q). At the DNA level, a greater proportion of patients (74%) showed loss of one chromosome 15q11-13 allele using a combination of densitometry and RFLP analysis. Deletion sizes were variable with 13 of 20 detectable both cytogenetically and with probe pML34 (D15S9). The remaining seven had microdeletions at the pML34 locus. Heterogeneity was further seen in three subjects who had cytogenetic deletions but normal DNA studies. In one patient there was evidence of a duplication at the pML34 locus. A new molecular rearrangement was identified with probe p3.21 (D15S10) in two patients and their mothers. Fifteen family studies were performed. In all 10 families where there was a molecular deletion, this was shown to have arisen de novo. DNA mapping confirmed that the paternal 15q allele was lost in three patients with PWS.