Meta-Biol

• Pathways

Chondroitin sulfate synthase 1 (CHSY1) (Kitagawa et al. 2001) possesses both beta-1,3-glucuronic acid and beta-1,4-N-acetylgalactosamine transferase activity, adding alternatingly the two building blocks GlcA and GalNAc to the growing chondroitin chain. Complete or almost complete loss of CHSY1 results in temtamy preaxial brachydactyly syndrome (TPBS; MIM:605282), an autosomal recessive characterized by limb malformations, short stature, and hearing loss. Mutations in CHSY1 leading to loss of function include E33Sfs*34, G19_L28del, P539R and Q69* (Temtamy et al. 1998, Li et al. 2010).