Update on Sitosterolemia and Atherosclerosis.

Since hypercholesterolemia is often present in individuals with sitosterolemia, it is important to search for genetic variants in ABCG5 and ABCG8 in patients with clinical criteria for familial hypercholesterolemia (FH), but no variants in FH implicated genes. Indeed, recent studies have suggested that genetic variants in ABCG5/ABCG8 can mimic FH, and even when in heterozygosis, they may potentially exacerbate the phenotype of patients with severe dyslipidemia. Sitosterolemia is a genetic lipid disorder characterized by increased circulating levels of plant sterols and clinically manifested by xanthomatosis, hematologic disorders, and early atherosclerosis. Awareness about this condition, a rare, but commonly underdiagnosed and yet treatable cause of premature atherosclerotic disease, is imperative.