Sperm chromosome complements in a man heterozygous for a reciprocal translocation t(2;3)(q24;p26)

Sperm chromosome complements were studied in a man heterozygous for a reciprocal translocation t(2;3)(q24;p26). This man was identified during a family study after his sister was investigated for amenorrhea. A total of 92 spermatozoa were karyotyped after in-vitro penetration of hamster eggs. The frequencies of alternate, adjacent 1, adjacent 2 and 3:1 segregations were 55.4, 36.1, 7.2 and 1.2% respectively. For alternate segregations, the number of normal spermatozoa (n = 25) was not significantly different from the number of spermatozoa carrying a balanced form of the translocation (n = 21), as theoretically expected. The proportion of spermatozoa with an unbalanced form of the translocation was 44.6%. There was no evidence for an interchromosomal effect since the frequencies of numerical and structural abnormalities (unrelated to the translocation) were within the normal range of control donors.