| Abstrakt: |
Sex chromosome mosaicism (45,XO/46XY karyotype) is often associated with an intersex phenotype and testicular dysgenesis. Undescended testes (cryptorchidism), hypospadias, and later on, infertility or subfertility and testicular cancer can be signs of testicular dysgenesis syndrome (TDS). The underlying reason is rarely a chromosomal abnormality, and for most cases, the etiology remains unknown. It has been hypothesized that genetic and environmental (including life style) factors that disturb gonadal development during pregnancy cause TDS, and the outcome depends on the timing and extent of the disruption. In mild cases, only spermatogenesis may be affected during adulthood, whereas in severe cases, the child may have hypospadias or develop testicular cancer at young age. The hypothesis is supported by clinical and epidemiological evidence that shows a strong association of the risks for each of the TDS signs, i.e. a boy with cryptorchidism has an increased risk of infertility and testicular cancer. Experimentally, we can induce TDS-like changes in animals by treating them with endocrine disrupting compounds. The challenge for the physicians treating TDS patients is to unravel the developmental mechanisms and causative agents. [ABSTRACT FROM AUTHOR] |
