Recombination and maternal age-dependent nondisjunction: Molecular studies of trisomy 16

Journal Article · Sun Oct 01 04:00:00 EDT 1995 · American Journal of Human Genetics

OSTI ID:237447

Hassold, T; Merrill, M; Adkins, K ^[1]

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1. Case Western Univ., and Univ. Hospitals, Cleveland, OH (United States); and others

Trisomy 16 is the most common human trisomy, occurring in {ge} 1% of all clinically recognized pregnancies. It is thought to be completely dependent on maternal age and thus provides a useful model for studying the association of increasing maternal age and nondisjunction. We have been conducting a study to determine the parent and meiotic stage of origin of trisorny 16 and the possible association of nondisjunction and aberrant recombination. In the present report, we summarize our observations on 62 spontaneous abortions with trisomy 16. All trisomies were maternally derived, and in virtually all the error occurred at meiosis I. In studies of genetic recombination, we observed a highly significant reduction in recombination in the trisomy-generating meioses by comparison with normal female meioses. However, most cases of trisomy 16 had at least one detectable crossover between the nondisjoined chromosomes, indicating that it is reduced-and not absent-recombination that is the important predisposing factor. Additionally, our data indicate an altered distribution of crossing-over in trisomy 16, as we rarely observed crossovers in the proximal long and short arms. Thus, it may be that, at least for trisomy 16, the association between maternal age and trisomy is due to diminished recombination, particularly in the proximal regions of the chromosome. 34 refs., 2 figs., 2 tabs.

• OSTI ID: 237447
• Journal Information: American Journal of Human Genetics, Journal Name: American Journal of Human Genetics Journal Issue: 4 Vol. 57; ISSN AJHGAG; ISSN 0002-9297
• Country of Publication: United States
• Language: English

Related Subjects

55 BIOLOGY AND MEDICINE
BASIC STUDIES
ABORTION
AGE DEPENDENCE
BIOLOGICAL MARKERS
CHROMOSOMAL ABERRATIONS
CROSSING-OVER
FEMALES
FETUSES
GENE RECOMBINATION
GENES
HUMAN CHROMOSOME 16
NON-DISJUNCTION
PREGNANCY
STATISTICS