Abstract
We have been using chromosome heteromorphisms and restriction fragment length polymorphisms (RFLPs) to investigate the mechanism of origin of trisomy 13, and the possible association between errors of recombination and the non-disjunctional event leading to trisomy. To date, we have studied 33 liveborn or spontaneously aborted trisomy 13 conceptions. By combining analysis of chromosome heteromorphisms with analysis of seven probes detecting chromosome 13 RFLPs, we have been able to determine the parental origin of 23 cases, with 20 being maternal and 3 paternal in origin.
In eight cases in which we have both cytogenetic and molecular information, we can make inferences regarding recombination in the two non-disjoined chromosomes. We have evidence for recombination in two of three cases in which the extra 13 originated in maternal meiosis I and in both instances this observation is based on results from several probes. This suggests that absence of recombination due to pairing failure is unlikely to be an important mechanism in the genesis of human trisomy. Furthermore, analysis of recombination in all eight cases provides no evidence for an association between reduced recombination and non-disjunction leading to trisomy 13, as has recently been suggested to be the case for trisomy 21.
Article PDF
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Hassold, T., Jacobs, P., Sheldon, M. et al. CYTOGENETIC AND MOLECULAR STUDIES OF NON-DISJUNCTION IN TRISOMY 13. Pediatr Res 21 (Suppl 4), 290 (1987). https://doi.org/10.1203/00006450-198704010-00738
Issue Date:
DOI: https://doi.org/10.1203/00006450-198704010-00738