title: Low density lipoprotein receptor gene Ava II polymorphism and serum lipid levels in the Guangxi Bai Ku Yao and Han populations.
abstract: BACKGROUND
  Several common genetic polymorphisms in the low density lipoprotein receptor (LDL-R) gene have associated with modifications of serum total cholesterol (TC) and low density lipoprotein cholesterol (LDL-C) levels, but the results are not consistent in different populations. Bai Ku Yao is a special subgroup of the Yao minority in China. The present study was undertaken to detect the association of LDL-R gene Ava Ⅱ polymorphism and serum lipid levels in the Guangxi Bai Ku Yao and Han populations.
  
  
  METHODS
  A total of 1024 subjects of Bai Ku Yao and 792 participants of Han Chinese were randomly selected from our previous stratified randomized cluster samples. Genotyping of the LDL-R gene Ava Ⅱ polymorphism was performed by polymerase chain reaction and restriction fragment length polymorphism combined with gel electrophoresis, and then confirmed by direct sequencing.
  
  
  RESULTS
  The levels of serum TC, high density lipoprotein cholesterol (HDL-C), LDL-C, apolipoprotein (Apo) A1 and the ratio of ApoA1 to ApoB were lower in Bai Ku Yao than in Han (P < 0.01 for all). The frequency of A⁻ and A+ alleles was 65.5% and 34.5% in Bai Ku Yao, and 80.7% and 19.3% in Han (P < 0.001); respectively. The frequency of A⁻A⁻, A⁻A+ and A+A+ genotypes was 42.6%, 45.9% and 11.5% in Bai Ku Yao, and 64.9%, 31.6% and 3.5% in Han (P < 0.001); respectively. There was also significant difference in the genotypic frequencies between males and females in Bai Ku Yao (P <0.05), and in the genotypic and allelic frequencies between normal LDL-C (≤ 3.20 mmol/L) and high LDL-C (> 3.20 mmol/L) subgroups in Bai Ku Yao (P < 0.05 for each) and between males and females in Han (P < 0.05 for each). The levels of LDL-C in males and TC and HDL-C in females were different among the three genotypes (P < 0.05 for all) in Bai Ku Yao, whereas the levels of HDL-C in males and HDL-C and ApoA1 in females were different among the three genotypes (P < 0.05-0.001) in Han. The subjects with A+A+ genotype had higher serum LDL-C, TC, HDL-C or ApoA1 levels than the subjects with A-A+ and A⁻A⁻ genotypes. Spearman rank correlation analysis revealed that the levels of LDL-C in Bai Ku Yao and HDL-C in Han were correlated with genotypes (P < 0.05 and P < 0.01; respectively).
  
  
  CONCLUSIONS
  The association of LDL-R gene Ava Ⅱ polymorphism and serum lipid levels is different between the Bai Ku Yao and Han populations. The discrepancy might partly result from different LDL-R gene Ava Ⅱ polymorphism or LDL-R gene-environmental interactions.
authors.affiliation: Department of Cardiology, Institute of Cardiovascular Diseases, the First Affiliated Hospital, 22 Shuangyong Road, Nanning 530021, Guangxi, People's Republic of China.
authors.forename: Xing-Jiang
authors.initials: XJ
authors.lastname: Long
authors.forename: Rui-Xing
authors.initials: RX
authors.lastname: Yin
authors.forename: Ke-La
authors.initials: KL
authors.lastname: Li
authors.forename: Wan-Ying
authors.initials: WY
authors.lastname: Liu
authors.forename: Lin
authors.initials: L
authors.lastname: Zhang
authors.forename: Xiao-Li
authors.initials: XL
authors.lastname: Cao
authors.forename: Lin
authors.initials: L
authors.lastname: Miao
authors.forename: Dong-Feng
authors.initials: DF
authors.lastname: Wu
authors.forename: Lynn Htet
authors.initials: LH
authors.lastname: Htet Aung
authors.forename: Xi-Jiang
authors.initials: XJ
authors.lastname: Hu
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D044466:Asian People / Q000235:genetics*; D001483:Base Sequence; D002681:China; D008076:Cholesterol, HDL / Q000097:blood; D008078:Cholesterol, LDL / Q000097:blood; D005006:Ethnicity / Q000235:genetics; D005260:Female; D005787:Gene Frequency; D005838:Genotype; D006801:Humans; D008055:Lipids / Q000097:blood*; D008297:Male; D008875:Middle Aged; D011110:Polymorphism, Genetic; D011973:Receptors, LDL / Q000235:genetics*
chemical_list: D008076:Cholesterol, HDL; D008078:Cholesterol, LDL; D008055:Lipids; D011973:Receptors, LDL