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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.

Background: Stromal cells play key roles during androgen-mediated male sexual differentiation. Our objective was to establish a transient transfection method for primary human fibroblasts enabling functional characterization of wild-type (wt) and mutant androgen receptor (AR) plasmid constructs, corresponding to partial and complete androgen insensitivity syndrome (PAIS/CAIS)., Methods: An AR-negative fibroblast strain (ARD842) was established from the gonads of a CAIS patient. Wt-AR or either mutants L712F (PAIS), R774C or V866M (CAIS) were transfected using a polyamine-based procedure. Alternatively, two AR-positive male foreskin fibroblast strains were investigated. Androgen-induced activation of two co-transfected reporter plasmids ((ARE)(2)TATA-, MMTV-luciferase) was measured., Results: All three fibroblast strains showed a ligand-dependent rise of luciferase activity after transfection of wt-AR. Mutant plasmids were assessed in AR-negative ARD842 cells. While L712F showed high partial activity, R774C and V866M were nearly inactive. The intrinsic AR of normal foreskin fibroblasts revealed no measurable ligand-inducible reporter gene activity., Conclusions: Polyamine-based transfection of AR plasmids into cultured fibroblasts provides a promising tool for analysis of AR transactivation, thereby considering a stromal cellular background. This is supported by the mutant ARs which showed the expected levels of impaired transactivation with respect to the corresponding AIS phenotypes. The role of the intrinsic AR in normal male human foreskin fibroblasts needs further exploration., (Copyright 2005 S. Karger AG, Basel.)

Androgen action is mediated in the peripheral target cell via the androgen receptor (AR). The AR is a nuclear transcription factor, combining a DNA-binding and a hormone-binding domain with a large transactivation unit. Androgen insensitivity syndrome (AIS) as the clinical entity of defective androgen action with variable phenotypes in 46,XY patients is caused by mutations of the X-chromosomal AR gene. Most variations in the AR gene are point mutations inhibiting either hormone or DNA binding. However, even within the same family, the phenotype for a given mutation can vary widely. Only few influential factors have been identified for the phenotypic diversity. For mutations affecting hormone binding, ligand concentration variability during fetal life may be an important influence on residual androgen action. A second factor is the occurrence of postzygotic de novo mutations, which are present at a high rate in single-case families. These somatic mutations lead to expression of both mutant and wild-type AR in a single patient and thus allow androgen action despite a deleterious mutation of the AR gene. Third, residual androgen response may be mediated by additional transcripts of the AR gene which are present in several cell types and can be affected in a different pattern by splice-site mutations. Whether differential expression of AR-interacting proteins has an influence on phenotype has not yet been proven. Moreover, little is known about the regulation of AR-dependent genes. Their identification is needed to understand post-AR action and, hence, androgenic control of sexual differentiation and maturation., (Copyright 2001 S. Karger AG, Basel)

Androgens have major influences on the regulation of bone mineralization. Because of their unique peripheral metabolism androgens may act on bone via activation of the androgen and/or estrogen receptor. Patients with complete androgen insensitivity syndrome (cAIS) are natural models to assess androgen actions on bone. We studied bone mineral density (BMD) in 10 patients with cAIS (mean age 13.70, range 4.7-19.8 years); 3 patients were studied before gonadectomy; the others were castrated and 6 were on hormonal replacement therapy. The BMD area (aBMD) was measured by dual energy X-ray; lumbar 'apparent' volumetric density (vBMD) was calculated using the formula vBMD = aBMD x [4/(pi x width)]. In the patients, aBMD (0.72 +/- 0.16 g/cm2) and vBMD (0.23 +/- 0.04 g/cm3) were significantly (p < 0.001) reduced in comparison with those of a control group (n = 15, age 5.0-20.5 years: aBMD 1.028 +/- 0.20 g/cm2; vBMD 0.35 +/- 0.04 g/cm3). Both aBMD and vBMD were also reduced in comparison with normal values for males (aBMD -2.66 +/- 0. 99 SDS, p < 0.001; vBMD -3.08 +/- 1.53 SDS, p < 0.0005) and females (aBMD -2.88 +/- 1.05 SDS, p < 0.001; vBMD -2.84 +/- 1.18 SDS, p < 0. 0007). Real lumbar bone density, assessed by computed tomography in 1 patient, was also reduced (-6.2 SDS and -3.5 SDS for male and female normal values, respectively). Biochemical markers of bone metabolism were normal and not significantly different in patients and controls. Girls with cAIS did not have more fractures than controls. In conclusion, both aBMD and vBMD are reduced in cAIS patients, while bone turnover and the fracture risk seem not to be increased. Our data indicate that both androgens and estrogens may be required for acquisition of bone density during childhood.

Boys are heavier than girls at term birth. Children with a 46,XY karyotype and androgen insensitivity syndrome (clinically complete form and/or proven mutations in the androgen receptor gene) were found to have a birth weight comparable to that of girls. These findings support the hypothesis that the difference in birth weight between boys and girls is generated by androgen action.

Truly feminine consciousness of gender identity, normal extragenital erotogenic sensitivity, suppressed or very reduced clitoris sensitivity and reaction, normal reaction of the labia minora and the vagina which deepens with the renewal of intercourse, realization of pleasure climax without clonicotonic orgasm and followed by resolution, and a normal maternal attitude seem to characterize sexual behavior in a complete or almost complete testicular feminization syndrome. These features allow one to clearly distinguish, without ignoring multiple psychologic mechanisms, the factors related to androgens and to estrogens in normal feminine sexual behavior.