Sitosterolemia (Phytosterolemia)

Excerpt

Sitosterolemia is a rare lipid disorder that is characterized by the accumulation of plant sterols in the blood. It is autosomal recessive and often presents in early childhood. Clinically, it can be misdiagnosed as familial hypercholesterolemia, and overlap between the two disorders creates a diagnostic challenge for physicians. Those with sitosterolemia absorb significantly higher amounts of plant sterols and stanols than healthy patients. This can lead to hypercholesterolemia and subsequent premature atherosclerosis. Patients can develop severe coronary artery disease, myocardial infarction, and other complications quite early in life if this condition is left untreated.

Due to its low prevalence and lack of unique clinical features, it is an underdiagnosed condition. Diagnostic testing is done by measuring a serum plant sterol level with subsequent genetic testing. Once diagnosed, it is a treatable condition with a combination of dietary modifications and medication. Elimination of plant sterols in the diet and treatment with ezetimibe generally leads to a major reduction in serum plant sterol levels.