The amount of a alpha-N-acetylgalactosaminide alpha-2,6-sialyltransferase 2 when measured in blood serum. The trait is level of alpha-N-acetylgalactosaminide alpha-2,6-sialyltransferase 2 in blood serum (Ontology of Biological Attributes identifier OBA_2043676). Also known as: blood serum alpha-N-acetylgalactosaminide alpha-2,6-sialyltransferase 2 amount.