Partial fra(X) phenotype with megalotestes in fra (X)-negative patients with acquired lesions of the central nervous system.

We describe 3 men with acquired lesions of the central nervous system (one male with tumor of the third ventricle, two males with peri- or postnatal accidents). In all three patients macroorchidism was associated with facial characteristics similar to those found in fra(X) males, but they were fra(X)-negative. The finding of megalotestes associated with a partial fra(X) phenotype in the present patients and, more particularly, the documentation of a hypothalamic tumor in the first patient, suggests that a specific hypothalamic lesion in fra(X) males is responsible for some of their manifestations.