Development of the ovaries and internal female reproductive organs is unaffected. Three quarters of affected infants have the severe salt-losing form, which is associated with vomiting and, from about 7 days after birth, signs of hyponatremic dehydration and hyperkalemia. These are all rare. In the last two disorders, the karyotype may be either This defect impairs the conversion of androstenedione to testosterone in the testis. Sixty cases have been reported from one inbred community in the Gaza Strip.
Inheritance is autosomal recessive.
Most XY cases have either ambiguous or female genitalia. In that group, at least 14 mutations in the 17beta-hydroxysteroid reductase 3 gene have been detected. This test would reveal an abnormally high ratio of androstenedione to testosterone in the serum. In this rare condition, affected XY subjects are born with ambiguous genitalia and at least one palpable testis, and are usually identified as female in childhood but undergo striking virilization at puberty. Nevertheless, the penis of adult patients is rarely greater than 6 cm in length.