The amount of a pterin-4-alpha-carbinolamine dehydratase 2 when measured in blood serum. The trait is level of pterin-4-alpha-carbinolamine dehydratase 2 in blood serum (Ontology of Biological Attributes term OBA_2042778). Also known as: blood serum pterin-4-alpha-carbinolamine dehydratase 2 amount.