Cytogenetic determinants of male fertility

BACKGROUND: Cytogenetic abnormalities have been known to be important causes of male infertility for decades. METHODS: Research publications from 1978 to 2008, from PubMed, have been reviewed. RESULTS: These studies have greatly improved our information on somatic chromosomal abnormalities such as translocations, inversions and sex chromosomal anomalies, and their consequences to the cytogenetic make-up of human sperm. Also, we have learned that infertile men with a normal somatic karyotype have an increased risk of chromosomally abnormal sperm and children. New techniques such as single sperm typing and synaptonemal complex analysis have provided valuable insight into the association between meiotic recombination and the production of aneuploid sperm. These meiotic studies have also unveiled errors of chromosome pairing and synapsis, which are more common in infertile men. CONCLUSIONS: These studies allow us to provide more precise information to infertile patients, and further our basic knowledge in the causes of male infertility.