Fragile sites and spontaneous abortions.

: In this report we present the cytogenetic findings of the expression of fragile sites in 10 couples with two or more spontaneous abortions. These findings were compared with the results in a control group of 15 subjects with two normal offsprings. Individuals of couples experiencing early fetal losses carry fragile sites with significant higher frequency, moreover this frequency is markedly influenced by the number of spontaneous abortions. Eight fragile sites were significantly more expressed in individuals with miscarriages than in the controls. These eight fragile sites correspond with cancer breakpoints or sites of oncogenes. Hypothesis on the role of oncogene mutations in spontaneous abortions is proposed, based on the results of the nonrandom distribution of fragile sites on human chromosomes.