Causes of infertility in men with Down syndrome

Men with Down syndrome are considered as infertile although the causes of infertility are not known in detail yet. Although this constitutes a general rule there are three confirmed cases of parenting by fathers with Down syndrome. Many investigators have addressed the causes of infertility and their studies indicate that the causes may be hormonal deficits, morphological alterations of the gonads, abnormal spermatogenesis, psychological and social factors related to the mental retardation. It is obvious that the extra chromosome 21 has a detrimental direct and indirect effect on the reproductive capacity of the affected male patient. But the definite cause of the insufficient and inadequate spermatogenesis remains to be discovered.