Potential effects of npc1l1 polymorphisms in protecting against clinical disease in a chinese family with sitosterolaemia

Sitosterolaemia is caused by mutations in either abcg5 or abcg8. chinese and japanese individuals usually have mutations in abcg5. we herein report a known and a novel mutation in abcg8 and their potential interaction with npc1l1 polymorphisms in a chinese family with sitosterolaemia. we sequenced abcg5 and abcg8 and measured the levels of plasma plant sterols in a 15-year-old chinese girl with clinical sitosterolaemia (xanthomas with elevated low-density lipoprotein cholesterol (ldl-c) and plant sterols) and her apparently healthy family members. npc1l1 was sequenced in the genetically affected sibling and other family members. a known mutation,c.490c＞t (p. arg164＊),in exon 4 and a novel mutation,c.1949t＞g (p.leu650arg),in exon 13 of abcg8 were detected in the proband and her sister,who had elevated sterols but low ldl-c levels and no xan-thomas. the genetically affected sister,but not the proband,carried two additional heterozygous changes in npc1l1 (rs2072183 c＞g,rs2301935 a＞c),which were inherited from the mother,who also had a low ldl-c level. in this study,we detected a known and a novel mutation in abcg8 in a chinese patient with sitosterolaemia. the same mutations were found in her clinically normal sister,suggesting that the contrasting features with the proband may be related to different variants in npc1l1 and/or some other undetermined lipid-related genetic factors. © 2014,japan atherosclerosis society. all rights reserved.