STAR and Aarskog-Scott syndrome, X-linked: In the case of FGD, 50% of cases are attributable to mutations in one of three genes: MC2R, MRAP, and STAR, which were linked to the disorder by traditional linkage and sequencing methods, but with the advent of next generation sequencing technologies, three further genes have been discovered and more causative genes may exist (Figure 1) (14, 17, 18, 28).