title: Prezygotic origin of the isochromosome 12p in Pallister-Killian syndrome.
abstract: Pallister-Killian syndrome is a rare disorder comprising multiple congenital anomalies, streaks of hypo(hyper)pigmentation, seizures, profound mental retardation, and the presence of an extra metacentric chromosome i(12)(p10), usually limited to skin fibroblasts. The mechanism and parental origin of the extra chromosome i(12)(p10) are unknown. Here, we present a girl with Pallister-Killian syndrome and the i(12)(p10) in 50% of cultured skin fibroblasts. Using microsatellite DNA markers of chromosome 12p, we detected 3 alleles--including 2 different alleles of maternal origin--in cultured skin fibroblasts, suggesting that the tetrasomy 12p is the result of a prezygotic event, with a nondisjunction event during maternal meiosis.
authors.affiliation: Unité de Recherches sur les Handicaps Génétiques de l'Enfant, INSERMU.393, Hôpital des Enfants Malades, Paris, France.
authors.forename: V
authors.initials: V
authors.lastname: Cormier-Daire
authors.forename: M
authors.initials: M
authors.lastname: Le Merrer
authors.forename: N
authors.initials: N
authors.lastname: Gigarel
authors.forename: N
authors.initials: N
authors.lastname: Morichon
authors.forename: M
authors.initials: M
authors.lastname: Prieur
authors.forename: S
authors.initials: S
authors.lastname: Lyonnet
authors.forename: M
authors.initials: M
authors.lastname: Vekemans
authors.forename: A
authors.initials: A
authors.lastname: Munnich
mesh_terms: D000015:Abnormalities, Multiple / Q000235:genetics*; D002881:Chromosomes, Human, Pair 12; D005260:Female; D005819:Genetic Markers; D006801:Humans; D007223:Infant; D008607:Intellectual Disability / Q000235:genetics*; D018404:Isochromosomes; D018895:Microsatellite Repeats; D010375:Pedigree; D012880:Skin Pigmentation / Q000235:genetics*; D013577:Syndrome
chemical_list: D005819:Genetic Markers