The amount of a alpha-N-acetylgalactosaminide alpha-2,6-sialyltransferase 3 when measured in blood serum. The trait is OBA_2043677 (level of alpha-N-acetylgalactosaminide alpha-2,6-sialyltransferase 3 in blood serum). Also known as: blood serum alpha-N-acetylgalactosaminide alpha-2,6-sialyltransferase 3 amount.