Primary Type I Hyperlipoproteinaemia—A Metabolic and Family Study

Abstract

Primary type I hyperlipoproteinemia is the rarest phenotype of the inherited hyperlipidemias. A study of the plasma lipids, lipoprotein distribution and apoprotein concentrations was carried out in a propositus and in 3 generations of her immediate family. The post heparin lipolytic activity (PHLA) was also studied. The propositus presented in infancy with spontaneous bruising and abdominal pain. She has gross chylomicronemia in the presence of depressed PHLA, which is due to deficiency of lipoprotein lipase. Apo (apoprotein) AI and B levels are depressed in concert with low density and high density lipoproteins. Introduction of a low fat diet resulted in loss of symptoms but plasma lipids remain abnormal. Within her immediate family, 6 of 9 members have depressed PHLA. Two such members have elevated plasma triglycerides, 1 associated with hypercholesteremia and peripheral vascular disease. Low PHLA in this family is associated with different lipoprotein phenotypes.