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Title: Molecular characterization of de novo secondary trisomy 13

Unbalanced Robertsonian translocations are a significant cause of mental retardation and fetal wastage. The majority of homologous rearrangements of chromosome 21 in Down syndrome have been shown to be isochromosomes. Aside from chromosome 21, very little is known about other acrocentric homologous rearrangements. In this study, four cases of de novo secondary trisomy 13 are presented. FISH using alpha-satellite sequences, rDNA, and a pTRI-6 satellite I sequence specific to the short arm of chromosome 13 showed all four rearrangements to be dicentric an apparently devoid of ribosomal genes. Three of four rearrangements retained the pTRI-6 satellite I sequence. Case 1 was the exception, showing a deletion of this sequence in the rearrangement, although both parental chromosomes 13 had strong positive hybridization signals. Eleven microsatellite markers from chromosome 13 were also used to characterize the rearrangements. Of the four possible outcomes, one maternal Robertsonian translocation, two paternal isochromosomes, and one maternal isochromosomes were observed. A double recombination was observed in the maternally derived rob(13q13q). No recombination events were detected in any isochromosome. The parental origins and molecular chromosomal structure of these cases are compared with previous studies of de novo acrocentric rearrangements. 20 refs., 3 figs., 2 tabs.
Authors:
; ;  [1] ;  [2] ; ;  [3] ; ;  [4]
  1. Baylor College of Medicine, Houston, TX (United States)
  2. Murdoch Institute, Melbourne (Australia)
  3. Pennyslvania Hospital, PA (United States)
  4. Henry Ford Hospital, Detroit, MI (United States)
Publication Date:
OSTI Identifier:
56845
Resource Type:
Journal Article
Resource Relation:
Journal Name: American Journal of Human Genetics; Journal Volume: 55; Journal Issue: 5; Other Information: PBD: Nov 1994
Country of Publication:
United States
Language:
English
Subject:
55 BIOLOGY AND MEDICINE, BASIC STUDIES; HUMAN CHROMOSOME 13; GENETIC MAPPING; MOLECULAR STRUCTURE; ACROCENTRIC CHROMOSOMES; CHROMOSOMAL ABERRATIONS; DNA HYBRIDIZATION; HUMAN POPULATIONS; MENTAL DISORDERS; DOWNS SYNDROME; HUMAN CHROMOSOME 21; DICENTRIC CHROMOSOMES; RECOMBINANT DNA