title: Parental origin of the extra chromosomes in polysomy X.
abstract: Five polymorphic index markers were analyzed by polymerase chain reaction (PCR) to ascertain the parental origin of the extra X chromosomes in seven polysomic cases (one 49,XXXXX, three 49,XXXXY, two 48,XXXY, and one 48,XXYY). All four X chromosomes in 49, X polysomies were maternal in origin and the extra X chromosomes in 48 X polysomies were paternal. In each case the multiple X chromosomes were contributed by a single parent. Taken together with previously reported cases, these data support a single mechanism of sequential nondisjunction during either maternal or paternal gametogenesis as the cause of higher order sex chromosome polysomy.
authors.affiliation: División de Genética, Guadalajara, Jal., Mexico.
authors.forename: C A
authors.initials: CA
authors.lastname: Leal
authors.forename: J W
authors.initials: JW
authors.lastname: Belmont
authors.forename: R
authors.initials: R
authors.lastname: Nachtman
authors.forename: J M
authors.initials: JM
authors.lastname: Cantu
authors.forename: C
authors.initials: C
authors.lastname: Medina
mesh_terms: D000328:Adult; D000782:Aneuploidy; D004247:DNA / Q000032:analysis; D005260:Female; D006801:Humans; D008297:Male; D009630:Nondisjunction, Genetic; D010290:Parents; D010375:Pedigree; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic; D014960:X Chromosome
chemical_list: D004247:DNA