Pylyp L. Meiotic segregation of translocations in sperm of infertile men

The dissertation focuses on the meiotic segregation analysis of structural balanced chromosomal rearrangements in sperm cells of infertile men, providing the theoretical basis for the improvement of genetic counselling of translocation carriers. Cytogenetic studies of GTG-banded lymphocyte chromosomes of 724 infertile men were analysed. Chromosomal abnormalities were detected in 48 individuals (6.6%). Structural balanced chromosomal rearrangements were observed in 32 persons (67%). Meiotic segregation patterns of 18 balanced structural chromosomal rearrangements were analysed by FISH method. The predominant formation of normal/balanced sperm was observed in Robertsonian translocation carriers (mean frequency 79,2 ± 8,4 %). Preferential formation of unbalanced sperm was detected in reciprocal translocation carriers (mean frequency 58,5 ± 6,5 %). Such results highlight differences in segregation of Robertsonian and reciprocal translocations in meiosis. Carriers of translocations are at increased risk of unbalanced sperm formation and pregnancy with chromosomally unbalanced fetus. The ineffectiveness of sperm selection based on morphological characteristics in real time under magnification of 6300 (MSOME) was shown, since no correlation between balanced chromosomal complement and morphology of sperm was observed.