CSGALNACT1 (Chondroitin Sulfate N-Acetylgalactosaminyltransferase 1): CSGALNACT1 is a gene that plays a key role in the biosynthesis of chondroitin sulfate, an essential component of the extracellular matrix in cartilage. It is important for cartilage development and proper joint function, and changes in its activity have been linked to skeletal disorders and joint diseases.