[The polymorphism of heterochromatin regions and aneuploidy in man (a review of the literature)].

Data over a 20-year period of investigation on C-polymorphism in parents of children with chromosome abnormalities, in couples with reproductive failures, and in patients with chromosome abnormalities are reviewed. The majority of the relevant evidence is suggestive of a relationship between C-polymorphisms and an enhanced risk of aneuploid progeny. It is suggested that phenomenon of "interchromosomal effect" of C-variants is accounted for by meiotic non-homologous co-orientation. Data on accumulation of marker variants in patients with chromosome abnormalities implicate the involvement of some prevalent segregation mechanism which is out of the limits of the models of meiosis considered.