This is the description of a clinical case of a newborn with a sexual differentiation disorder. Among the clinical manifestations present were malformed genitalia, bilaterally palpable gonads along the inguinal canal, a split scrotum, and a small penis resembling a clitoris.
The presence of gonads in the inguinal canals was confirmed sonographically. Cytogenetics testified for karyotype 46, XY.
According to performed laboratory tests no rare form of hormone disorder of the adrenal hormonogenesis was found. The ratio of testosterone and dihydrotestosterone did not prove a 5α reductase deficiency.
Molecular-genetic examinations found an AR gene mutation (locus Xq11-12, OMIM *313700), which is linked to the androgen insensitivity syndrome. This rare X-linked disorder is manifested by inadequate virilisation of the male external genitalia in individuals with a XY karyotype.
We discuss the multidisciplinatory approach in the diagnosis of sexual differention disorders in newborns and the many factors that play a role in the definitive choise of gender.