Sitosterolemia (also known as phytosterolemia) is a rare autosomal recessively inherited lipid metabolic disorder. It is characterized by hyperabsorption and decreased biliary excretion of dietary sterols leading to hypercholesterolemia, tendon and tuberous xanthomas, premature development of atherosclerosis, and abnormal hematologic and liver function test results.

Epidemiology:

Only 45 cases have been reported in the literature worldwide, hence this condition appears to be relatively rare. More than likely, sitosterolemia is significantly underdiagnosed and many patients are probably misdiagnosed with hyperlipidemia.