Identification and treatment of heterozygous familial hypercholesterolemia in children and adolescents.

Heterozygous familial hypercholesterolemia (FH) is completely expressed at birth and early in childhood by significant elevations in plasma total and low density lipoprotein (LDL) cholesterol levels. High density lipoprotein cholesterol can be low in such FH children; the triglyceride levels are usually within the normal range. Screening of children for heterozygous FH using a LDL cholesterol level is reasonably efficient in families with known FH, but for general population screening, the LDL cholesterol level is often too nonspecific. Screening of offspring with a positive family history of premature coronary artery disease will provide a panoply of different lipoprotein phenotypes, reflecting the presence of other genetic conditions, including familial combined hyperlipidemia. Guidelines have been developed by the National Cholesterol Education Program (NCEP) Expert Panel on Blood Cholesterol levels in Children and Adolescents to assist in the evaluation and treatment of children with high LDL cholesterol levels. Although heterozygous FH probably counts for < or = 5% of premature coronary artery disease, its identification and treatment are important, because FH often causes marked premature coronary artery disease early in adulthood, and can be successfully treated with a combined dietary and drug approach.