Biochemical and endocrine heterogeneity in the complete form of testicular feminization syndrome

A familial variant of male pseudohermaphroditism different from the classical form of the complete testicular feminization syndrome was studied. The three affected 46, XY sibling (16,18 and 20 years old) exhibited female phenotype identical to that of a 17 years old patient with the classical form, included as a control. The major endocrine and biochemical differences observed in this family, as compared with the classical form, includes: a. Markedly elevated serum levels of LH and FSH; b. Non-elevated serum testosterone levels; c. Poor testicular hCG responsiveness; d. Abnormally elevated baseline and hCG-stimulated androstenedione: testosterone ratio; e. Slight pituitary responsiveness to androgens; f. presence of residual androgen uptake by cultured fibroblasts derived from genital skin. These differences were more evident in the two older patients. All subjects presented a lack of nitrogen retention following testosterone administration. These results were interpreted as demonstrating a testicular impairment of testosterone biosynthesis in the older subjects of this family, which resulted in an unusual gonadotropin profile. The altered androstenedione: testosterone ratio suggests a secondary partially decreased activity of testicular 17-hidroxysteroid dehydrogenase, as demonstrated in TFM mice and rats. The overall data indicate an age-dependent variability in the expression of androgen insensitivity in this family, thus demonstrating the wide biochemical heterogeneity of the androgen resistant syndromes.