The effect of 13;14 Robertsonian translocations on germ-cell differentiation in infertile males.

Two infertile men heterozygous for a 13;14 Robertsonian (Rb) translocation were investigated by means of synaptonemal complex studies, testicular histology, and semen analysis. In both individuals interaction between the Rb trivalent and the XY pair was observed. Twenty percent of pachytene cells analyzed in one patient showed XY-trivalent association which correlated with malformed spermatids; the higher rate of XY-trivalent association (approximately 47%) in the second proband corresponded with complete spermatogenic arrest. The data presented indicate a positive correlation between increased frequency of XY trivalent association and the degree of germ-cell impairment.