Question

Discuss the effects on sex determination of the AR and the SRD5A2 mutations.

Answer 1

SRD5A2 deficiency results from a defect in the enzyme that converts testosterone to DHT. DHT is responsible for the differentiation of male external genitalia. Mutations in SRD5A2 result in undermasculinized external genitalia.

Male infants with mutations in SRD5A2, the degree of ambiguity ranges from isolated hypospadias to severe undermasculinization.

In male puberty stage, the development of male secondary sex characteristics, such as male body habitus, deepening of the voice, and penile enlargement can occur. However, these individuals have unusually fine upper lip hair.