title: U-type exchange in a paracentric inversion as a possible mechanism of origin of an inverted tandem duplication of chromosome 8.
abstract: A mentally retarded male with dysmorphic features was found to have a de novo 46,XY,inv dup(8) (p.23.1-->12). Confirmation of the segments duplicated in the rearrangement was achieved by biochemical analysis of glutathione reductase, which maps to 8p21.1, and DNA studies using the chromosome specific probe y-19-1D (D85131), which maps to 8p21. Assay of cathepsin B, which has been localised to 8p22, did not differ from controls with normal chromosomal constitution. DNA studies using the Defensin 1 gene probe, which maps to 8p23, showed a previously undetected deletion of that segment. We propose that the inverted tandem duplication/deletion arose as a single U-type exchange within an inversion loop.
authors.affiliation: Divisions of Medical Genetics, Montreal Children's Hospital, McGill Centre for Human Genetics, Quebec, Canada.
authors.forename: J J
authors.initials: JJ
authors.lastname: Mitchell
authors.forename: M
authors.initials: M
authors.lastname: Vekemans
authors.forename: S
authors.initials: S
authors.lastname: Luscombe
authors.forename: M
authors.initials: M
authors.lastname: Hayden
authors.forename: B
authors.initials: B
authors.lastname: Weber
authors.forename: A
authors.initials: A
authors.lastname: Richter
authors.forename: R
authors.initials: R
authors.lastname: Sparkes
authors.forename: T
authors.initials: T
authors.lastname: Kojis
authors.forename: G
authors.initials: G
authors.lastname: Watters
authors.forename: V M
authors.initials: VM
authors.lastname: Der Kaloustian
mesh_terms: D000015:Abnormalities, Multiple / Q000235:genetics; D002675:Child, Preschool; D007446:Chromosome Inversion; D002898:Chromosomes, Human, Pair 8; D005145:Face / Q000002:abnormalities; D006801:Humans; D008607:Intellectual Disability / Q000235:genetics*; D007621:Karyotyping; D008297:Male; D005810:Multigene Family