GROWTH of sexual hair in a young child suggests the possibility that adrenal tumor or hyperplasia may be causing virilization or that true sexual precocity may be beginning. However, neither of these relatively serious conditions may exist. Approximately 10 years ago workers in the Endocrine Clinic of the Harriet Lane Home became aware of the fact that sexual hair may appear in early life long before there is any other secondary sexual development dependent upon either androgen or estrogen. Although this syndrome has been referred to briefly in textbooks as "precocious adrenarche" and "premature pubarche," no detailed studies of a series of cases have been recorded.
The present report is based on a study of 29 children who developed sexual hair before the age of 8 years. It was possible to follow a number of these patients long enough to demonstrate that the condition is a benign variation in the pattern of sexual development and is followed later by normal adolescence. It seems important to bring the findings to the attention of pediatricians who may not be familiar with the syndrome and to discuss its differential diagnosis and probable etiology.
Methods
Urinary 17-ketosteroids (17-KS) were determined by a modification of the method of Callow, Callow and Emmons previously described, urinary estrogens were measured as the "fluorogenic phenols" by the method of Jailer. Vaginal smears stained by the method of Shorr were interpreted as described elsewhere. The "bone age" was based on the average epiphysial development at all the joints.
Clinical and Laboratory Findings
Mouse Fem1b interacts with the Nkx3.1 homeoprotein and is required for proper male secondary sexual development
