Cytogenetic analysis of sperm from a male heterozygous for a 13;14 Robertsonian translocation.

Cytogenetic analysis of 121 sperm from a man heterozygous for a t(13;14) Robertsonian translocation was performed using the technique of in vitro penetration of hamster eggs. The frequency of sperm that were chromosomally unbalanced with respect to the translocation was 27%. The frequency of chromosomally normal (36%) and balanced (38%) complements was approximately equal, as theoretically expected. There was no evidence for an interchromosomal effect since the frequency of numerical chromosomal abnormalities (2.5%) and structural chromosomal abnormalities (10.7%)--both unrelated to the translocation--were within the normal range of control donors. The ratio of X- and Y-chromosome bearing sperm was equal, and there was no evidence for preferential segregation of the X chromosome with the translocation.