Definition

A dominantly inherited genetic condition that results in markedly elevatedLDL (low-density lipoprotein) cholesterol levels beginning at birth, and resulting in heart attacks at an early age.

Alternative Names

Type II hyperlipoproteinemia; Hypercholesterolemic xanthomatosis; Low density lipoprotein receptor mutation

Causes

Affected people have consistently high levels of low-density lipoprotein, which leads to prematureatherosclerosis of the coronary arteries. Typically in affected men, heart attacks occur in their 40s to 50s, and 85% of men with this disorder have experienced a heart attack by age 60. The incidence of heart attacks in women with this disorder is also increased, but delayed 10 years later than in men.

Individuals from families with a strong history of early heart attacks should be evaluated with a lipid screen. Proper diet, exercise, and the use of newer drugs can bring lipids down to safer levels.

It is possible for a person to inherit two genes for this disorder. This magnifies the severity of the condition. Cholesterol values may exceed 600 mg/cc. Affected individuals develop waxy plaques (xanthomas) beneath the skin over their elbows, knees, buttocks. These are deposits of cholesterol in the skin. In addition, they develop deposits in tendons and around the cornea of the eye. Atherosclerosis begins before puberty and heart attacks and death may occur before age 30.

Review Date: 3/2/2004
Reviewed By: A.D.A.M. editorial. Douglas R. Stewart, M.D., Division of Medical Genetics, Hospital of the University of Pennsylvania, Philadelphia, PA. Review provided by VeriMed Healthcare Network (8/21/2003).