Sperm segregation analysis of a complex chromosome rearrangement, 2;22;11, by whole chromosome painting

Using the human sperm-hamster oocyte fusion technique and whole chromosome painting, we studied sperm chromosome segregation in a male heterozygous for a complex chromosome rearrangement, 46,XY,-2,+der(2)t(2; 11)(q13; q23),-11,+der(11)t(11;22)(q23;q11.2),-22,+der(22)t(2;22)(q13; q11.2). A total of 208 sperm complements were analyzed. The frequency of sperm carrying a normal or a balanced complement was 13.5% (9.62% and 3.85%, respectively). The frequency of unbalanced sperm was 86.5% (64.9% from 3:3 segregation, including 30 different types; 20.7% from 4:2 segregation, including 21 different types; and 0.96% from 5:1 segregation, including 2 different types). The sex ratio, determined in 134 sperm complements, did not differ from the expected 1:1 ratio. The results obtained in this study are compatible with the formation, during the synaptic process, of a complex hexavalent figure involving chromosomes 2, 11, and 22. The behavior and segregation of this complex figure would explain the high frequency (86.5%) of unbalanced complements observed in this carrier.