A systematic review of ABCG8 mutation and sitosterolemia.

Background: Sitosterolemia is a rare inherited condition caused by elevated levels of plant sterols in the plasma, characterized by mutations in ABCG5 and ABCG8 genes. A scarce occurrence in this condition are hematological abnormalities such as hemolytic anemia, stomatocytosis, and macrothrombocytopenia. We conducted a meta-analysis and systematic review to answer these questions regarding patients who have hemolytic anemia and ABCG8 mutation.

Methods: 13 reports were shortlisted for the final analysis (Observational studies-6, case series-4, case reports-3). Descriptive statistics were utilized to study the patient characteristics.

Results: From the 13 reports that we found in available literature, we identified 19 cases of ABCG8 mutation and anemia. From the random-effects proportions model, the chance of this event occurring among patients with sitosterolemia was 6.8% [0.068, 95% Confidence Interval (CI) 0.016-0.120, P=0.010] (I² 24.68%) (14/145). Thrombocytopenia and stomatocytosis were frequently reported. Splenomegaly and xanthomas were other common associations.

Conclusions: To the best of our knowledge, we provide the first report of the prevalence of anemia, specifically in patients with sitosterolemia caused by a mutation in the ABCG8 gene. At 6.8%, this is an extremely rare occurrence in an already infrequent disease.