Chylomicronemia, Familial, Due To Circulating Inhibitor Of Lipoprotein Lipase

Brunzell et al. (1983) described a mother and her son with hyperlipoproteinemia type I (the chylomicronemia syndrome), very low levels of postheparin plasma lipolytic activity, and circulating inhibitor of lipoprotein lipase, who differed from subjects with lipoprotein lipase deficiency (238600) in that the enzyme was present in adipose tissue at much higher levels than those seen in normal subjects. They also differed from subjects with deficiency of apolipoprotein C-II (207750) in that apolipoprotein C-II was present in their plasma in normal or elevated amounts. They appeared to have an inhibitor to lipoprotein lipase activity that inhibited that activity eluted from adipose tissue with heparin and that activity present in postheparin of normals. The inhibitor was nondialyzable, heat-stable, and sensitive to repeated freezing and thawing; it appeared to be present in the nonlipoprotein fraction of plasma. The same abnormality may have been present in her father and grandson; if the latter is true, this would be an instance of male-to-male transmission. The mother was a 47-year-old white woman who was found to have massive hypertriglyceridemia after developing eruptive xanthomas on the outer aspects of both feet. Plasma triglyceride level was 3,865 mg/dl. She had a history of recurrent undiagnosed abdominal pain since the age of 16 years. Alcohol intake was minimal and she was not taking any hormone preparations. The spleen was palpable. She was not obese. Dietary fat restriction reduced triglyceride levels and prevented recurrent attacks of pancreatitis. Her father had died at age 39 years after surgery for acute abdominal pain. Her only son, aged 21 years, had marked hypertriglyceridemia but was asymptomatic and had no xanthomas or hepatosplenomegaly. She had a grandson who at 4 months of age had grossly lipemic plasma with triglyceride of 2400 mg/dl and cholesterol of 246 mg/dl.