The relevance of chromosomal aberrations in male infertility

Abstract

Based on the results of chromosome analysis from cell cultures and testis biopsies, the incidence of chromosomal abnormalities in infertile men is up to 20%. Chromosomal analysis from peripheral blood cultures is a routine procedure while the analysis of meiotic chromosomes is labor intensive and mainly used in a scientific setting. Of all infertile males, 7-9% show numerical and/or structural chromosomal abnormalities in their peripheral blood lymphocytes. There is an inverse correlation between sperm count and the incidence of chromosomal abnormalities, with 21% of patients with non-obstructive azoospermia having a chromosomal abnormality, most often Klinefelter's syndrome. The rate of patients with chromosomal abnormalities is only 9% in patients with severe oligozoospermia (less than 5 million/ml),and structural abnormalities are found more often in this group. Using fluorescence in situ analysis the number of selected chromosomes can be assayed in single sperm cells. There is no consensus on whether infertile men have a higher proportion of aneuploid (disomic) sperm cells than fertile men. Taking into account the results from meiotic studies in infertile men,an increased rate of aneuploid sperm cells is likely. Chromosomal analysis should be performed on all infertile men being treated with ICSI as the result of this analysis could have important consequences in their reproductive decisions.