title: Mechanism of intrachromosomal triplications 15q11-q13: a new clinical report.
abstract: We describe here a patient with intrachromosomal triplication 15q11-q13, a rare chromosomal event associated with severe mental retardation and intractable epilepsy. Cytogenetic studies including FISH on interphasic nuclei showed that the middle segment of the triplication was inverted in orientation. Molecular analyses demonstrated that the rearrangement was of maternal origin. Based on these cytogenetic and molecular data and those of the nine cases reported in the literature, we discuss the mechanistic origins of these triplications. We present several arguments for the mechanism involving two U-type exchanges occurring simultaneously at the pachytene stage of meiosis.
authors.affiliation: Laboratoire de Cytogénétique, CHU de Rouen, Rouen, France.
authors.forename: François
authors.initials: F
authors.lastname: Vialard
authors.forename: Cécile
authors.initials: C
authors.lastname: Mignon-Ravix
authors.forename: Dominique
authors.initials: D
authors.lastname: Parain
authors.forename: Danielle
authors.initials: D
authors.lastname: Depetris
authors.forename: Marie-France
authors.initials: MF
authors.lastname: Portnoï
authors.forename: Hélène
authors.initials: H
authors.lastname: Moirot
authors.forename: Marie-Geneviève
authors.initials: MG
authors.lastname: Mattei
mesh_terms: D000328:Adult; D002467:Cell Nucleus / Q000648:ultrastructure; D002874:Chromosome Mapping; D002884:Chromosomes, Human, Pair 15; D003582:Cytogenetics; D004827:Epilepsy / Q000235:genetics*; D005192:Family Health; D005260:Female; D020440:Gene Duplication; D005819:Genetic Markers; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D008607:Intellectual Disability / Q000235:genetics*; D008297:Male; D008540:Meiosis; D008957:Models, Genetic; D010375:Pedigree
chemical_list: D005819:Genetic Markers