Abstract
Three sisters with plasma lecithin: cholesterol acyltransferase deficiency have been studied. Precipitates were demonstrated between their serum and anti-α1-lipoprotein by Ouchterlony technique. The α1-lipoprotein of the patients exhibited atypical behaviour in immunoelectrophoretic tests, in preparative ultracentrifugation, and by gel filtration on Sephadex G-200.