MCM4 and Aarskog-Scott syndrome, X-linked: 3). Patients with FGD generally present with Addisonian symptoms, including hyperpigmentation of skin and mucous membranes, with the important distinction that mineralocorticoid production is preserved (3). FGD has been associated with mutations in seven genes: MC2R, MRAP, STAR, CYP11A1, NNT, MCM4, and TXNRD2 (3, 4). Most commonly (50% of cases), MC2R and MRAP defects are responsible.