Association of ATP binding cassette transporter G8 rs4148217 SNP and serum lipid levels in Mulao and Han nationalities

Background: The association of ATP binding cassette transporter G8 gene (ABCG8) rs4148217 single nucleotide polymorphism (SNP) and serum lipid profiles is still controversial in diverse racial/ethnic groups. Mulao nationality is an isolated minority in China. The aim of this study was to evaluate the association of ABCG8 rs4148217 SNP and several environmental factors with serum lipid levels in the Guangxi Mulao and Han populations. Methods: A total of 634 subjects of Mulao nationality and 717 participants of Han nationality were randomly selected from our previous samples. Genotyping of the ABCG8 rs4148217 SNP was performed by polymerase chain reaction and restriction fragment length polymorphism combined with gel electrophoresis, and then confirmed by direct sequencing. Results: The genotypic and allelic frequencies of ABCG8 rs4148217 SNP were different between the two nationalities (P<0.01 for each), the frequency of A allele was higher in Mulao than in Han. The A allele carriers in Han had lower high-density lipoprotein cholesterol (HDL-C) and apolipoprotein (Apo) A1 levels than the A allele noncarriers (P<0.05 for each), whereas the A allele carriers in Mulao had lower ApoA1 levels than the A allele noncarriers (P<0.05). Subgroup analyses showed that the A allele carriers in Han had lower HDL-C and higher triglyceride (TG) levels in females but not in males than the A allele noncarriers (P<0.05 for each), and the A allele carriers in Mulao had lower ApoA1 levels in females but not in males than the A allele noncarriers (P<0.05). The levels of TG and HDL-C in Han, and ApoA1 in Mulao were associated with genotypes in females but not in males (P<0.05-0.01). Serum lipid parameters were also correlated with several environmental factors (P<0.05-0.001). Conclusions: The ABCG8 rs4148217 SNP is associated with serum TG, HDL-C and ApoA1 levels in our study populations, but this association is different between the Mulao and Han populations. There is a sex (female)-specific association in both ethnic groups.