First, nine patients with a deletion involving DAX1 alone presented with isolated X-linked AHC, while two patients (P38 and P39) at risk for the metabolic crisis or phenotypic characteristics of hypotonia and ID were found to have the deletion extended to contain the IL1RAPL1, DAX1, GK and DMD genes. Here, GK is linked to X-linked adrenal hypoplasia congenita.