Normal bone density in male pseudohermaphroditism due to 5alpha- reductase 2 deficiency.

UNLABELLED Bone is an androgen-dependent tissue, but it is not clear whether the androgen action in bone depends on testosterone or on dihydrotestosterone. Patients with 5alpha-reductase 2 deficiency present normal levels of testosterone and low levels of dihydrotestosterone, providing an in vivo human model for the analysis of the effect of testosterone on bone. OBJECTIVE To analyze bone mineral density in 4 adult patients with male pseudohermaphroditism due to 5alpha-reductase 2 deficiency. RESULTS Three patients presented normal bone mineral density of the lumbar column (L1-L4) and femur neck, and the other patient presented a slight osteopenia in the lumbar column. CONCLUSION Patients with dihydrotestosterone deficiency present normal bone mineral density, suggesting that dihydrotestosterone is not the main androgen acting in bone.