The pathogenic gene of MCD is the carbohydrate sulfotransferase 6-(CHST6, MIM 605294) gene, which is located on chromosome 16q23.1 (which contains four exons), and exon 3 encodes the CHST6 (C-GlcNAc6ST, EC 2.8.2.-), comprising 395 amino acids. Here, CHST6 is linked to macular corneal dystrophy.