Clinical and molecular genetic analysis of a family with sitosterolemia and co-existing erythrocyte and platelet abnormalities.

We describe the clinical, biochemical and molecular genetic features of a Chinese family with sitosterolemia, mainly manifested by hematologic abnormalities. The clinical features of three patients were analyzed. Their plasma sterol levels were measured, and ABCG5 and ABCG8 genes sequenced to search for the causative mutation. The main clinical features of these patients were hemolysis and macrothrombocytopenia; they had increased plasma sitosterol but maintained normal cholesterol levels. Sequence analysis revealed a novel Gln22X nonsense mutation in exon 1 or ABCG5. Our results suggest that blood cells could be a target for the toxic effect of plasma phytosterols; the coexisting hematologic abnormalities might represent a specific subtype of sitosterolemia.