Genetic dyslipoproteinemias

Abstract

Familial lipid disorders rarely present with xanthomas in the case of children with homozygous familial hypercholesterolemia (FH) or adolescents with heterozygous FH. Usually lipid disorders are found fortuitously or upon screening children fromfamilies with a known lipid disorder or high cardiovascular risk. In the case of homozygous FH, cholesterol lowering is imperative to prevent aortic root disease and sudden death fromacutemyocardial infarction or acute coronary insufficiency before 30 years of age. In all other cases, treatment should be planned according to the childs risk level for cardiovascular disease (or rarely, pancreatitis). To determine the risk level, the family history, lowdensity lipoprotein (LDL) cholesterol level, and other risk factors, including diabetes, high-density lipoprotein (HDL) cholesterol level, smoking, hypertension, and obesity should be evaluated. Preferably, the childrens treatment should be managed by an experienced outpatient lipid or pediatrics unit that includes a dietician. The diagnosis of lipid disorders is based on the results of at least two lipid profiles (total cholesterol, HDL cholesterol, LDL cholesterol, triglycerides, apolipoproteinB, and,optionally, apolipoprotein AI)obtainedafteranovernight fast. Children with high LDL cholesterol or triglyceride levels should then have a detailed history (including the family history of cardiovascular disease), review of systems, and physical examination, with selected laboratory testing to exclude secondary causes of hyperlipidemia. Lipid profiles fromthe parents and other familymembers may be needed to help identify primary hyperlipidemias associated with genetic abnormalities of lipoprotein metabolism.