Sitosterolemia

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 (including the phytosterol beta-sitosterol). Healthy persons absorb only about 5% of dietary plant sterols, but sitosterolemia patients absorb 15% to 60% of ingested sitosterol without excreting much into the bile. It's named after the most abundant phytosterol in the diet, sitosterol, though other phytosterols are also involved. The phytosterol campesterol is more readily absorbed than sitosterol.

Sitosterolemia patients develop hypercholesterolemia, tendon and tuberous xanthomas, premature development of atherosclerosis, and abnormal hematologic and liver function test results.