Abstract. To clarify the origin of the genital ambiguity occasionally associated with the XX male syndrome, a series of endocrinological studies were undertaken in an affected 6 months old infant with perineoscrotal hypospadias. The patient fulfilled all the diagnostic criteria of the syndrome: the testes were descended bilaterally, the Mullerian derivatives were absent, the 46,XX chromosome complement was ascertained in different cell lines, and male levels of H-Y antigen were detected in cultured skin fibroblasts. Circulating gonadotrophin levels and pituitary LRH responsiveness were within normal limits for the age group. Serum testosterone (T) levels were normal, and gonadal stimulation with hCG caused a significant rise on serum T. Incubations of [3H]T with fibroblasts from genital skin revealed normal activity of steroid 5α-reductase. Moreover, normal concentrations of thermostable cytosol androgen receptors were revealed in cultured fibroblasts. Altogether the results indicated that ambiguity of the external genitalia in this patient was the result of neither abnormal T biosynthesis, peripheral A-ring T reduction, nor androgen intracellular specific binding, and suggested that the nature of the imcomplete virilization could be a non-endocrine independent event associated to this disorder. The data are also consistent with the notion that testicular impairment observed in adult XX males develops later in life.
An Infertility SRY-Negative 46, XX Male Detected by Quantitative Fluorescent Polymerase Chain Reaction
