In contrast, different individually rare causes of PAI as X-linked AHC (NR0B1/DAX-1), autosomal adrenal hypoplasia (NR5A1/SF-1), congenital lipoid adrenal hyperplasia (CYP11A1, STAR gene defects), FGD, adrenal autoimmune destruction and adrenoleukodystrophy (ABCD1) are now well established [15, 16]. Here, ABCD1 is linked to X-linked adrenal hypoplasia congenita.