Puberty in subjects with complete androgen insensitivity syndrome

BACKGROUND: Androgen receptor defects affect the regulation of the gonadotropic axis. However, little is known about the timing of pubertal maturation in complete androgen insensitivity syndrome (CAIS). AIMS: To evaluate growth, skeletal maturation and gonadotropin and sex steroid secretion in patients with CAIS and intact gonads at puberty. METHODS: Clinical, auxological and hormonal evaluation of 9 patients with CAIS from birth up to 17 years of age, prior to gonadectomy, in a single institution, retrospective study. RESULTS: Breast development occurred at a median age of 11.1 years, thumb sesamoid appeared at 11.5 years, and peak height velocity at 12.3 years, all consistent with average female values. However, median adult male height (+1.2 SDS) was closer to the patients' male target height (-0.3 SDS). Plasma testosterone levels rose early compared to normal boys. LH (basal and GnRH-stimulated) increased rapidly, above normal male values, in early puberty. CONCLUSIONS: This retrospective evaluation of a limited number of cases with a heterogeneous pattern of follow-up suggests that patients with CAIS may enter puberty at an age closer to female standards. These results imply a major role of direct androgen action, in utero or in early life, in determining the pattern of pubertal gonadotropin maturation.