ATCS, adducted-thumb club foot syndrome; Abs, antibodies; B3GALT6; BMP, bone morphogenetic proteins; C4ST, chondroitin 4-sulfotransferase; C6ST, chondroitin 6-sulfotransferase; COLLI, type I collagen; COLLIII, type III collagen; COLLV, type V collagen; COLLs, collagens; COMP, cartilage oligomeric matrix protein; CS, chondroitin sulfate; CSGALNACT1, chondroitin sulfate N-acetylgalactosaminyltransferase 1; CTDs, connective tissue disorders; Cartilage oligomeric matrix protein; ChPF, chondroitin polymerizing factor; ChSy, chondroitin synthase; D4ST, dermatan 4 sulfotransferase 1; DCN, decorin; DEGs, differentially expressed genes; DS, dermatan sulfate; ECM, extracellular matrix; EDS, Ehlers­Danlos syndrome; Ehlers­Danlos syndrome; FN, fibronectin; GAGs, glycosaminoglycans; GO, gene ontology; Gal, galactose; GalNAc, N-acetylgalactosamine; GalNAc4S-6ST, GalNAc 4-sulfate 6-O-sulfotransferase; GalNAcT, ß1,4-N-acetylgalactosaminyltransferase; GalNAcT-16, N-acetylgalactosaminyltransferase 16; GalT-I/II, galactosyltransferase I and II; GalT-II deficiency; GlcA, glucuronic acid; GlcAT, glucuronosyltransferase; GlcNAc, N-acetylglucosamine; GlcNAcT, α1,4-N-acetylglucosaminyltransferase; HA, hyaluronic acid; HAS2, hyaluronan synthase 2; HOX, homeobox gene family; HPO, human phenotype ontology; HS, heparan sulfate; Hep, heparin; IF, immunofluorescence microscopy studies; IdoA, iduronic acid; OPN, osteopontin; Osteopontin; PGs, proteoglycans; PTC, premature termination codon of translation; SEMDJL1, spondyloepimetaphyseal dysplasia with joint laxity type 1; Spondyloepimetaphyseal dysplasia with joint laxity type 1; TNs, tenascins; Xyl, xylose; XylT, xylosyltransferase; qPCR, quantitative polymerase chain reaction