Chromosomal anomalies as a predisposing factor for male infertility

A "genetic factor" can be the reason for about 20% of male infertility cases. This could be due to chromosomal aberrations in sperm with immediate effect on conception or may result in recurrent spontaneous abortions of paternal origin. Techniques for the analysis of sperm chromosomal aberrations are still far from ideal. Sperm penetration to zona-free hamster oocytes and random in situ hybridization with sperm DNA using a range of fluorescent probes--are currently under investigation. Sperm chromosome analysis was performed in three distinct subgroups, (a) healthy, fertile individuals, (b) healthy but infertile subjects, and (c) carriers of chromosomal aberrations in lymphocytes. Sperm chromosomal aberrations occur in normal and fertile population in range from 1.9% to 15.8%. The aberrations are concerned both with number and structure of chromosomes. In infertile individuals, the main chromosome aberrations observed were translocations and pericentric inversions. Several hypotheses are also described indicating possible reasons for subfertility due to chromosomal anomalies. There are few gene families that can be involved in the regulation of spermatogenesis, mainly located on the Y-chromosome. Identification of defective gene(s) may lead to novel therapeutic strategies for infertility treatment.