The amount of a chondroitin sulfate N-acetylgalactosaminyltransferase 2 when measured in blood serum. The trait is level of chondroitin sulfate N-acetylgalactosaminyltransferase 2 in blood serum (Ontology of Biological Attributes term OBA_2041167). Also known as: blood serum chondroitin sulfate N-acetylgalactosaminyltransferase 2 amount.