The amount of a peroxisome proliferator-activated receptor gamma coactivator 1-alpha when measured in blood serum. The trait is level of peroxisome proliferator-activated receptor gamma coactivator 1-alpha in blood serum (Ontology of Biological Attributes id OBA_2042980). Also known as: blood serum peroxisome proliferator-activated receptor gamma coactivator 1-alpha amount.