The fragile site on chromosome 16 (q21q22). Data on four new families.

The significance of the fragile site on 16 (q21q22) has not yet been fully evaluated. New data will contribute to the understanding of this cytogenetic finding. Therefore we report on four families where a chromosome 16 with fragile site was segregating and such problems as infertility, abortions, malformations, and aneuploidy were present. The hypothesis that this fragile site is a site of viral modification (or integration?) is considered.