Genetic origin of spermatogenesis impairments: clinical aspects and relationships with mouse models of infertility.

Human spermatogenesis failures appear frequently as idiopathic and may be due to genetic causes. Mutations of genes involved in the hypothalamic/pituitary control of spermatogenesis have been described and account for several types of hypogonadotropic hypogonadism. Chromosomal abnormalities found in infertile patients are either gonosomal aneuploidies or structural anomalies which interfere with the normal chromosome behaviour at meiosis and lead to germ cell breakdown. Microdeletions of the Y chromosome are often undetectable at karyotype and are responsible for the loss of genes which compose the AZF factor. The increase in the number of mouse models of infertility will allow the description of many human genes involved in the spermatogenesis process provided that a detailed analysis of their genotype–phenotype relationships is performed. [ABSTRACT FROM AUTHOR]