The amount of a 1-phosphatidylinositol 3-phosphate 5-kinase when measured in blood. The trait is level of 1-phosphatidylinositol 3-phosphate 5-kinase in blood (OBA_2051625, an Ontology of Biological Attributes identifier). Also known as: blood 1-phosphatidylinositol 3-phosphate 5-kinase amount.