The amount of a 1-phosphatidylinositol 4,5-bisphosphate phosphodiesterase beta-1 when measured in blood serum. The trait is level of 1-phosphatidylinositol 4,5-bisphosphate phosphodiesterase beta-1 in blood serum (OBA_2042918, an Ontology of Biological Attributes entry). Also known as: blood serum 1-phosphatidylinositol 4,5-bisphosphate phosphodiesterase beta-1 amount.