The genetic basis of male infertility

Defective spermatogenesis can be the end result of a multitude of causes, s uch as systemic disease, malnutrition, endocrinologic disorder, genetic def ects, anatomic obstruction of the passage of spermatozoa, infections, and e nvironmental toxins. A genetic basis of infertility is thought to exist in a majority of infertile men currently classified as having idiopathic infer tility Despite advances in molecular technology, the pathophysiology of spe rmatogenic failure in a majority of infertile men remains unknown. Although a large number of genes and loci in experimental animals are associated wi th sterility, the human homologues of most of these genes have not been clo ned yet. Infertility is a heterogeneous syndrome in men; therefore, it is l ikely that a multitude of genes and loci will be implicated in different in fertility subsets.