Specific 5α-dihydrotestosterone binding in labial skin fibroblasts c1ultured from patients with male pseudohermaphroditism

Abstract

The cytoplasm of skin fibroblasts serially subcultured from the labium majus of normal human females binds 5.alpha.-dihydrotestosterone (5.alpha.-DHT) with high affinity and low capacity. Such binding was absent from the strains of 2 male pseudohermaphrodites with unambiguous female external genitalia. One of these was from a patient with the clinical features and a family history typical of complete testicular feminization; the other merited the same diagnosis on anatomic and endocrine grounds, but had an XYY karyotype in multiple tissues, including the testes. Normal cytoplasmic binding was found in strains from 2 prepubertal male pseudohermaphrodites with bilateral inguinal testes. One had unambiguous female external genitalia, the other had clitoromegaly; the former had normal specific nuclear binding of 5.alpha.-DHT, and thereby the target cell capacity for pubertal masculinization. Measurement of specific 5.alpha.-DHT binding by cultured labial skin fibroblasts should be an early step in the investigation of male pseudohermaphroditism with female external genitalia.