STAR and Aarskog-Scott syndrome, X-linked: Mutations in steroidogenic acute regulatory (STAR) protein are known to give rise to lipoid congenital adrenal hyperplasia, a severe form of adrenal insufficiency characterized by both glucocorticoid and mineralocorticoid deficiency together with gonadal deficiency; however, STAR mutations have also been identified in a number of patients with FGD suggesting that mutations in this gene can give rise to a spectrum of clinical phenotypes encompassing FGD (Metherell et al., 2009).