Autosomal recessive hypercholesterolemia in three sisters with phenotypic homozygous familial hypercholesterolemia: diagnostic and therapeutic procedures.

Familial hypercholesterolemia is an autosomal-dominant inherited disorder caused by mutations in the low-density lipoprotein (LDL) receptor gene. The homozygous form is characterized by high-serum LDL cholesterol concentrations, xanthoma formation and premature atherosclerosis. Recently, another molecular defect that also results in severely elevated LDL cholesterol levels was identified: autosomal recessive hypercholesterolemia.