Thus, our data provide new insights into the molecular mechanisms that control the tissue- and developmental-specific expression of these two critical genes and identify GATA4 as a potential causative factor in cases of abnormal human sex development such as Frasier syndrome (XY male-to-female sex reversal with intact SRY gene) and DDS syndrome (incomplete sex differentiation associated with reduced AMH levels). The gene discussed is SRY; the disease is Frasier syndrome.