title: Unique karyotypes in two patients with Prader-Willi syndrome.
abstract: A physical disruption of the Prader-Willi syndrome (PWS) chromosome region is thought to cause PWS. We describe 2 girls with PWS phenotype, who had unique chromosome 15 abnormalities. The first patient showed mosaicism: 45,XX,t(15;15)(qter----p11.1::q11.200----qter)/46,XX,t(15;15)(qter----p1 1.1::q 11.200----qter), +mar. The band 15q11.2 apparently remained intact in the t(15;15) chromosome, and the mar chromosome was considered as r(15) (p11.1q11.1). The second patient had a karyotype of 47,XX,del(15)(q11.200----q11.207), +idic (15)(pter----q11.1::q11.1----pter). The complex breakage and reunion involving the 15q11.2 regions of the father's homologous chromosomes 15 at meiosis appeared to have resulted in the idic(15) and the del(15) chromosomes. These cytogenetic findings suggest that the PWS chromosome region may be localized on the very proximal portion of band 15q11.2.
authors.affiliation: Department of Pediatrics, Okayama University Medical School, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Narahara
authors.forename: K
authors.initials: K
authors.lastname: Hiramoto
authors.forename: M
authors.initials: M
authors.lastname: Murakami
authors.forename: S
authors.initials: S
authors.lastname: Miyake
authors.forename: K
authors.initials: K
authors.lastname: Tsuji
authors.forename: Y
authors.initials: Y
authors.lastname: Yokoyama
authors.forename: H
authors.initials: H
authors.lastname: Namba
authors.forename: S
authors.initials: S
authors.lastname: Ninomiya
authors.forename: R
authors.initials: R
authors.lastname: Murakami
authors.forename: Y
authors.initials: Y
authors.lastname: Seino
mesh_terms: D002648:Child; D002869:Chromosome Aberrations / Q000235:genetics*; D002871:Chromosome Banding; D002872:Chromosome Deletion; D025063:Chromosome Disorders; D002884:Chromosomes, Human, Pair 15; D005260:Female; D006801:Humans; D007223:Infant; D007621:Karyotyping; D009030:Mosaicism / Q000235:genetics; D011218:Prader-Willi Syndrome / Q000235:genetics*