Sitosterolemia-An Underdiagnosed and Heterogeneous Lipid Disorder. A Case Series From a Tertiary Care Centre in Australia.

Aims: Sitosterolemia, is a disorder of increased plant sterol levels leading to a variable presentation and haematological manifestations. Although considered rare, the prevalence is likely underestimated due to the variable phenotype and challenges in diagnosis. The delayed diagnosis may lead to cardiovascular complications. We reviewed the presentation and management of patients with sitosterolemia in our clinic.

Method: We report 4 children aged 18 months to 18 years with variable manifestations from xanthomas to haemolytic anaemia who were subsequently confirmed to have sitosterolemia on genetic testing.

Results: One patient presented with xanthomas, two patients with haematological manifestations and the other with an abnormal lipid profile. All patients had a strong family history of lipid disorders and cardiovascular disease at a young age. All patients had confirmatory genetic testing and were managed with dietary adjustments and ezetimibe resulting in improvement of lipid and haematological profiles.

Conclusion: Sitosterolemia is a likely underdiagnosed lipid disorder due to variable phenotype and specialised genetic and biochemical diagnostic tests. Early diagnosis and treatment fully reverse the clinical manifestations and associated complications.