[Genetic factor of sex determination].

We have analyzed 40 cases of human XX male or XX true hermaphrodites negative for Y DNA sequences including ZFY. Among these patients we were able to demonstrate the existence of at least 3 mechanisms. 1) In one case a mosaïscism 46XY/46XX is limited to the gonad and only detected by PCR. 2) Familial cases compatible with the mutation of an autosomal (or pseudo-autosomal) down stream sex determining gene. 3) We finally observed 5 cases lacking ZFY meanwhile carrying Y specific sequences near to the pseudo-autosomal boundary, redifining the region where TDF must lie.