Macular corneal dystrophy has mostly been correlated with mutations in the carbohydrate sulfotransferase 6 (CHST6) gene, which encodes the enzyme carbohydrate sulfotransferase 6, which catalyzes the transfer of a sulfate group to the GlcNAc residue of KS (Hasegawa et al., 2000). The gene discussed is CHST6; the disease is macular corneal dystrophy.