title: Family studies in Prader-Willi syndrome.
abstract: Clinical, cytogenetic and molecular studies have been undertaken in the families of 52 probands with Prader-Willi syndrome. The maternal age at the birth of a proband with a deletion in 15p11q13 was on average 8 years less than that of the mothers of probands with uniparental disomy (UPD), the paternal age was on average 7 years less. Seven probands with UPD were all female, as were 7 patients who had neither a detectable chromosomal abnormality nor UPD. Cytogenetic and molecular polymorphisms in proximal chromosome 15 indicated that for probands with a 15q11q13 deletion, inheritance of both the maternal and the intact paternal homologue is random in their unaffected sublings. Pigmentation studies suggest that probands who have a deletion in 15q11q13 have lighter colouring than other family members implying that D15S12 may not be imprinted.
authors.affiliation: Department of Clinical Genetics, Birmingham Maternity Hospital, Edgbaston, U.K.
authors.forename: T
authors.initials: T
authors.lastname: Webb
authors.forename: C A
authors.initials: CA
authors.lastname: Hardy
authors.forename: M
authors.initials: M
authors.lastname: Dahlitz
authors.forename: E
authors.initials: E
authors.lastname: Watkiss
authors.forename: D
authors.initials: D
authors.lastname: Clarke
mesh_terms: D000328:Adult; D002648:Child; D002872:Chromosome Deletion; D002874:Chromosome Mapping; D002884:Chromosomes, Human, Pair 15; D015342:DNA Probes; D005260:Female; D006801:Humans; D008297:Male; D008957:Models, Genetic; D010641:Phenotype; D016133:Polymerase Chain Reaction; D011218:Prader-Willi Syndrome / Q000175:diagnosis / Q000235:genetics*
chemical_list: D015342:DNA Probes