Genetic, Epigenetic, and Non-Genetic Factors in Testicular Dysgenesis Syndrome: A Narrative Review

Testicular dysgenesis syndrome (TDS) is a complex disorder of the male reproductive system related to disfunction of the fetal testis. The clinical features of TDS may be evident at birth or infancy (cryptorchidism, hypospadias and/or reduced anogenital distance) or occur later in adulthood (testis cancer, infertility). Genetic background seems to be important for genetic predisposition, with new genes being associated with components of the syndrome in last years. Interestingly, the incidence of clinical manifestations of TDS has been increasing in many countries in recent decades, suggesting that genetic predisposition alone cannot explain this trend. Consequently, the hypothesis of multifactorial etiopathogenesis is becoming increasingly accepted nowadays, with environmental factors probably acting during early developmental stages in genetically predisposed individuals.

In this narrative review, we aim to critically evaluate genetic and non-genetic factors involved in the pathogenesis of TDs.

Important associations with intrauterine growth disorders and maternal diseases (overweight/obesity and diabetes) as well as lifestyle factors (e.g., smoking and alcohol abuse) were found. In such context, endocrine disruptors probably play a major role. These substances are widely used in industry and can exert estrogenic and antiandrogenic effects, potentially interfering with the development of the fetal gonad.

Considering their possible impact on male sexual health, more attention should be focused on maternal modifiable factors to confirm with prospective studies the mixed results of available evidence.