Female phenotype in a male child due to 17-alpha-hydroxylase deficiency.

The discovery of testicles in a 3-year-old girl with XY karyotype led to a diagnosis of testicular feminization. Subsequently, however, hypokalaemia, hypertension, and severe prostration during a mild infection suggested adrenal involvement, and investigations showed a 17-alpha-hydroxylase deficiency. Diagnosis of testicular feminization should not be made without excluding a defect of testosterone synthesis.