Abstract: Objective To identify the low-density lipoprotein-receptor(LDL-R)gene mutations in three Chinese families with familial hypercholesterolemia and xanthomatosis,and to investigate the relationship between the genotype and phenotype of this disease.Methods Serum lipids levels were measured,and clinical examinations were performed in 3 probands and 25 family members.The LDL-R gene was assessed with PCR-denaturing high performance liquid chromatography and DNA sequencing.The sequencing results were blasted with the standard sequence of LDL-R gene in GenBank to identify the mutation sites.Results In all three probands,xanthoma was found at the buttock at birth.As they got older,more xanthomas developed at many areas of the body with corneal arcus formation,which confirmed the diagnosis of familial hypercholesterolemia and xanthomatosis.The heterozygous mutation of LDL-R gene,D601N and C122Y, was detected in proband 1 and 2,respectively.No mutation was observed in proband 3.A total of 4 heterozygous patients were confirmed in 28 family members.Conclusion The D601N and C122Y mutations of LDL-R gene may be the cause of familial hypercholesterolemia and xanthomatosis in Chinese.

Key words: Xanthomatosis, Hypercholesterolemia,familial, Receptors,LDL, Mutation