CHST3 and spondyloepiphyseal dysplasia with congenital joint dislocations: Spondyloepiphyseal dysplasia with congenital joint dislocations, CHST3 type (SEDCJD, MIM 143095), also named recessive Larsen syndrome, is due to biallelic variants in the CHST3 gene, encoding for carbohydrate sulfotransferase-3, also known as chondroitin 6-sulfotransferase 1 (C6ST-1).