Catalyzes the first step in the biosynthesis of chondroitin sulfate and dermatan sulfate proteoglycans, such as DCN. Transfers D-xylose from UDP-D-xylose to specific serine residues of the core protein (PubMed:15461586, PubMed:17189265, PubMed:23982343, PubMed:24581741). Required for normal embryonic and postnatal skeleton development, especially of the long bones (PubMed:23982343, PubMed:24581741). Required for normal maturation of chondrocytes during bone development, and normal onset of ossif

Golgi apparatus membraneSecreted

Desbuquois dysplasia 2

A chondrodysplasia characterized by severe prenatal and postnatal growth retardation (less than -5 SD), joint laxity, short extremities, progressive scoliosis, round face, midface hypoplasia, prominent bulging eyes. The main radiologic features are short long bones with metaphyseal splay, a 'Swedish key' appearance of the proximal femur (exaggerated trochanter), and advance carpal and tarsal bone age. Two forms of Desbuquois dysplasia are distinguished on the basis of the presence or absence of characteristic hand anomalies: an extra ossification center distal to the second metacarpal, delta phalanx, bifid distal thumb phalanx, and phalangeal dislocations.