Human male infertility: chromosome anomalies, meiotic disorders, abnormal spermatozoa and recurrent abortion

Human male infertility is often related to chromosome abnormalities.In chromosomally normal infertile males, the rates of chromosome21 and sex chromosome disomy in spermatozoa are increased. Higherincidences of trisomy 21 (seldom of paternal origin) and sexchromosome aneuploidy are also found. XXY and XYY patients produceincreased numbers of XY, XX and YY spermatozoa, indicating anincreased risk of production of XXY, XYY and XXX individuals.Since XXYs can reproduce using intracytoplasmic sperm injection(ICSI), this could explain the slight increase of sex chromosomeanomalies in ICSI series. Carriers of structural reorganizationsproduce unbalanced spermatozoa, and risk having children withduplications and/or deficiencies. In some cases, this risk isconsiderably lower or higher than average. These patients alsoshow increased diploidy, and a higher risk of producing diandrictriploids. Meiotic disorders are frequent in infertile males,and increase with severe oligoasthenozoospemia (OA) and/or highfollicle stimulating hormone (FSH) concentrations. These patientsproduce spermatozoa with autosomal and sex chromosome disomies,and diploid spermatozoa. Their contribution to recurrent abortiondepends on the production of trisomies, monosomies and of triploids.The most frequent sperm chromosome anomaly in infertile malesis diploidy, originated by either meiotic mutations or by acompromised testicular environment.