The presence of androgen-binding receptors in genital and nongenital skin fibroblasts. 
The specific, receptor-dependent 5 alpha-dihydrotestosterone-binding capacity of cultured fibroblasts derived from genital and nongenital skin has been compared.  With the methods employed, the detectable amount of the DHT receptor in nongenital skin-derived fibroblasts is variable, often approaching the limit of detectability.  Therefore it is concluded that for differential diagnosis of disorders of sexual development, DHT-binding studies should be performed with genital skin fibroblasts only.