Cryptorchidism, or failure of testicular descent, is a common human congenital abnormality with a multifactorial etiology that likely reflects the involvement of endocrine, environmental, and hereditary factors. Cryptorchidism can result in infertility and increases risk for testicular tumors. Testicular descent from abdomen to scrotum occurs in 2 distinct phases: the transabdominal phase and the inguinoscrotal phase (summary by Gorlov et al., 2002).

Hermaphroditism refers to a discrepancy between the morphology of the gonads and that of the external genitalia. In male pseudohermaphroditism, the genotype is male (XY) and the external genitalia are imcompletely virilized, ambiguous, or complete female. If gonads are present, they are testes.

A genital phenotype that is not clearly assignable to a single gender. Ambiguous genitalia can be evaluated using the Prader scale

Development of the reproductive system is inconsistent with the chromosomal sex.