Definition An über rare autosomal recessive disorder (OMIM:210250) characterised by increased intestinal absorption of all sterols including cholesterol, plant and shellfish sterols, and reduced excretion of dietary sterols into bile. These patients have hypercholesterolemia, high levels of plant sterols in plasma, and develop tuberous xanthomas, accelerated atherosclerosis and premature coronary artery disease.
Molecular pathology Defects of:
• ABCG5—which encodes a transporter that selectively transports dietary cholesterol in and out of enterocytes and selectively excretes sterols by the liver into bile, and
• ABCG8—which encodes a transporter that excludes non-cholesterol sterols from entering the intestine, drives excretion of cholesterol and sterols into bile, and facilitates recycling of sterols into the intestinal lumen,
Synonyms Acrothrombocytopaenia/stomatocytosis—Mediterranean type, phytosterolaemia