CHST14 and Ehlers-Danlos syndrome, musculocontractural type: Musculocontractural Ehlers–Danlos Syndome (mcEDS) is a type of EDS caused by biallelic pathogenic variants in the gene for carbohydrate sulfotransferase 14/dermatan 4-O-sulfotransferase 1 (CHST14/D4ST1, mcEDS-CHST14), or in the gene for dermatan sulfate epimerase (DSE, mcEDS-DSE).