Clinical, genetic profile and therapy evaluation of 55 children and 5 adults with sitosterolemia

•Blood lipid levels may predict the age and location of xanthoma occurrence.•Dietary therapy was the cornerstone of sitosterolemia treatment.•Ezetimibe lowered blood lipid levels and increased dietary phytosterol tolerance.•Sixteen novel variants in ABCG5/ABCG8 expanded genetic spectrum of sitosterolemia.•Q251X (ABCG5) was only reported in Chinese sitosterolemia patients.