Approximately 25 of 100 000 children are born with an atypical appearance of their genitalia as part of a more or less defined disorder of sex development (DSD). Due to improved medical knowledge and better classification, the aetiology and pathophysiology behind a growing number of these cases have been clarified, although a large number still remains obscure with respect to the underlying biology. In line with this, there are growing insights into the functional consequences for sex differentiation of chromosomal aberrations and defined genetic defects. However, many cases of DSD seem to be associated with environmental rather than genetic causes. Data to support this comes from recently observed trends of declines in human male fertility in parallel with reports on poorer semen quality in young adult males. Further, solid reports on recent increases of testis germ cell cancer also point to an environmental origin. Congenital abnormalities in boys such as cryptorchidism and hypospadias also appear to be increasing, at least in certain regions. Such geographical variations strengthen the possible association with environmental factors. Endocrine disrupting chemicals (EDCs) is the term used for an expanding number of exogenous chemicals with the ability to influence the endocrine system. EDCs have been firmly associated with observations made world-wide on malformations and dysfunctions of the reproductive system in different species of wild-life and there is emerging evidence of such associations also in humans. In experimental models EDCs have been found to disrupt gonadal maturation and function, with a particular vulnerability of the testis. Androgen production by Leydig cells is critical for normal male pre and postnatal testicular development and constitutes an important target of EDC actions. This presentation will give an overview of the concept of environmental disruption of testicular function with focus on the possible role of some defined EDCs.
Funding: Swedish Paediatric Cancer Fund; Swedish Research Council.
01 Oct 2015 - 03 Oct 2015