PIKFYVE and macular corneal dystrophy: For example, mutations in six genes (CHST6, OMIM 605294; UBIAD1, OMIM 611632; SLC4A11, OMIM 610206; PIKFYVE, OMIM 609414; TACSTD2, OMIM 137290; DCN, and OMIM 125255) have found a direct genetic association with macular corneal dystrophies (MCD), Schnyder CD (SCD), congenital hereditary endothelial dystrophy (CHED), fleck CD (FCD), gelatinous drop-like CD (GDLD), and congenital stromal CD (CSCD), respectively, (Zhang et al., 2013).