The amount of a methylmalonate-semialdehyde/malonate-semialdehyde dehydrogenase [acylating], mitochondrial when measured in blood serum. The trait is OBA_2040565 (level of methylmalonate-semialdehyde dehydrogenase [acylating], mitochondrial in blood serum). Also known as: blood serum methylmalonate-semialdehyde/malonate-semialdehyde dehydrogenase [acylating], mitochondrial amount.