Cytogenetics of infertile men

Chromosomally derived sterility has long been recognized. A review of the literature of somatic chromosome investigations in infertile males has shown that 13.7% of azoospermic males and 4.6% of oligozoospermic males have an abnormal karyotype. In the first group, sex chromosome abnormalities predominate (mainly 47,XXY), whereas in the latter, autosome anomalies (i.e. Robertsonian and reciprocal translocations) are the most frequent. A similar review on meiotic studies revealed that meiotic chromosome anomalies can explain male infertility in 4.3-40.4% of patients. Recently, fluorescent in-situ hybridization studies on spermatozoa from infertile men were published; it was suggested that both X-Y pairing and pairing of the autosomes were impaired, resulting in spermatogenic disruption. We investigated cytogenetically 694 infertile men with abnormal sperm parameters. More patients are needed for this research to investigate the relationship, if any, between the type of chromosome abnormality and its influence on the number, morphology and motility of spermatozoa. To be able to provide proper counselling for those couples whose male infertility can now be treated by intracytoplasmic sperm injection, it is suggested that clinical investigations should include mitotic and meiotic studies, an analysis of the chromosome content of individual spermatozoa and a DNA analysis of blood and spermatozoa to detect partially deleted Y chromosome material.