Androgen binding in cultured human fibroblasts from patients with idiopathic hypospadias

Androgens stimulate development and growth of the external male genitalia. Since hypospadias represents the most common congenital abnormality in the male newborn and the mechanism of action in this disorder is still unclear, androgen binding was assessed in cultured fibroblasts from biopsies from genital skin of 10 patients with idiopathic hypospadias. For comparison, binding was determined in corresponding samples from 8 males with normal penile development and from 9 patients with known androgen resistance syndromes (testicular feminization, Reifenstein syndrome, pseudovaginal perineoscrotal hypospadias). Finally, binding was measured in 10 samples of nongenital skin. Maximum specific binding (Bmax) in idiopathic hypospadias varied from 3.2 to 15.5 (median 6.6) fmol.mg protein-1. Bmax in samples of persons with normal genital development was between 12.2 and 17.9 fmol.mg protein-1 (median 13.2). Bmax in samples of patients with known androgen resistance syndromes was exactly in the range reported previously in the literature. It is evident that Bmax in samples of patients with idiopathic hypospadias differs significantly (P less than 0.01), (Mann Whitney U-test) from those with normal genital development. Thus it seems reasonable to conclude that in some patients with idiopathic hypospadias the genital defect is caused by receptor deficiency.