This gene encodes a member of the chondroitin N-acetylgalactosaminyltransferase family. The encoded protein is involved in elongation during chondroitin sulfate synthesis. A related pseudogene has been identified on chromosome X. Transfers 1,4-N-acetylgalactosamine (GalNAc) from UDP-GalNAc to the non-reducing end of glucuronic acid (GlcUA). Required for addition of the first GalNAc to the core tetrasaccharide linker and for elongation of chondroitin chains.