ESPE Abstracts

Background: Sitosterolaemia, or phytosterolaemia, is a disorder of increased plant sterol levels in the body leading to a variable presentation including hypercholesteremia, xanthoma, atherosclerosis and haematological manifestations. Although considered rare, the prevalence is likely underestimated due to the variable phenotype. It is caused by recessively inherited mutations in ABCG5 or ABCG8 which encode the sterol efflux transporters in the gut. Hypercholesterolaemia is often mild in adults but more marked in young children. The diagnosis may be missed unless plant sterol levels are checked using gas spectrometry or liquid spectrometry or genetic testing is performed based on clinical suspicion. The delayed diagnosis may lead to cardiovascular disease. Management is with dietary modification to reduce foods high in plant sterols in addition to Ezetimibe which inhibits sterol absorption. Statins are not usually indicated. Reduction in plant sterol levels can lead to improvement in cardiovascular outcome and haematological manifestations.

Case series: We report 4 children aged 18 months to 18 years who presented to our lipid clinic with variable manifestations from xanthmoas to haemolytic anaemia and were subsequently confirmed to have sitosterolaemia on genetic testing. All patients had a strong family history of lipid disorders and cardiovascular disease at a young age. All have responded to dietary modifications and Ezetimibe.

Conclusion: Sitosterolaemia may be missed or underdiagnosed due to the spectrum of clinical presentation ranging from asymptomatic to cardiovascular and haematological complications. Specialised testing for plant sterol levels and genetic mutations are needed to confirm the diagnosis. The clinical features can be fully reversed by dietary modification and Ezetimibe.