Combined deficiency of apolipoprotein C-II and lipoprotein lipase in familial hyperchylomicronemia.
The underlying pathophysiological defect was studied in four siblings with familial hyperchylomicronemia. Deficiency of apolipoprotein C-II and E-3 was identified. In addition, these subjects had markedly decreased LPL activity in postheparin plasma. Addition of normal plasma to the assay as source for apoC-II enhanced LPL activity only to a limited extent. In contrast with previously reported patients with apoC-II deficiency, a far less pronounced effect of intravenous infusion of normal plasma was seen in one of the siblings, probably due to the combined deficiency of apoC-II and LPL. Plasma VLDL-TG turnover rate was not decreased in one of the siblings with apoC-II and LPL deficiency, suggesting different metabolic pathways for chylomicrons and VLDL. Family study confirmed an autosomal recessive mode of inheritance both for apoC-II and for apoE-3 deficiency. The mode of inheritance for LPL deficiency could not be established exactly.
D000328:Adult; D053304:Apolipoprotein C-II; D001053:Apolipoproteins / Q000097:blood / Q000172:deficiency*; D001056:Apolipoproteins C; D005215:Fasting; D005260:Female; D006801:Humans; D008072:Hyperlipoproteinemia Type I / Q000097:blood* / Q000201:enzymology / Q000235:genetics; D006951:Hyperlipoproteinemias / Q000097:blood*; D008049:Lipase / Q000097:blood; D008071:Lipoprotein Lipase / Q000097:blood / Q000172:deficiency*; D008074:Lipoproteins / Q000097:blood; D008099:Liver / Q000201:enzymology; D008297:Male; D010375:Pedigree; D014280:Triglycerides / Q000097:blood
D053304:Apolipoprotein C-II; D001053:Apolipoproteins; D001056:Apolipoproteins C; D008074:Lipoproteins; D014280:Triglycerides; D008049:Lipase; D008071:Lipoprotein Lipase