ABSTRACT
Familial hypercholesterolemia Familial hypercholesterolemia (FH) is an autosomal dominant inherited lipid disorder caused by one of the many mutations in the gene for the LDL receptor, leading to increased total cholesterol and LDL-cholesterol levels (two times elevated), typical tendon xanthomata, and premature atherosclerosis.The clinical expression varies widely and is influenced by other risk factors.The disorder occurs in 1 in 400-500 individuals; in certain areas in the world, the incidence is much higher due to a founder effect. Homozygous patients with two mutated LDL receptor alleles (total serum cholesterol four times elevated) develop xanthomata and atherosclerosis at a young age. If untreated they usually die before the age of 20-30 years due to complications of vascular disease.The FH clinical phenotype can also result from mutations in the gene for apolipoprotein B, the ligand of LDL for the LDL receptor. In addition to common mutations in the LDL receptor and apolipoprotein B genes, two rare mutations in genes involved in cholesterol metabolism have recently been described to cause severe hypercholesterolemia.The following case is a typical example of a patient with a severe clinical FH phenotype.
