STGD (STGD1, ABCA4, OMIM #601691: autosomal recessive homozygous or heterozygous; SGDT4, PROM1, OMIM #604365: autosomal dominant heterozygous; STGD3, ELOVL4, OMIM #600110: autosomal dominant STGD-like macular dystrophy) is the most common form of macular dystrophy in young adults with onset typically in childhood or early adulthood. The gene discussed is ABCA4; the disease is Macular dystrophy.