The amount of a dihydroorotate dehydrogenase (quinone), mitochondrial when measured in blood serum. The trait is Ontology of Biological Attributes entry OBA_2041294 (level of dihydroorotate dehydrogenase (quinone), mitochondrial in blood serum). Also known as: blood serum dihydroorotate dehydrogenase (quinone), mitochondrial amount.