[Relationship between the polymorphism of the variable number of tandem repeats region 3' of the apolipoprotein B gene and serum lipid levels in the Guangxi Heiyi Zhuang populations].

Objective: To study the relationship between the polymorphism of the variable number of tandem repeats region 3' of the apolipoprotein B gene (3'APOB-VNTR) and serum lipid levels in the Guangxi Heiyi Zhuang population.
Methods: A total of 548 people of Heiyi Zhuang nationatity were surveyed by a cluster sampling. Epidemiological data were collected and serum lipid and apolipoprotein levels were measured. The genotypes and alleles of the 3' APOB-VNTR were determined by polymerase chain reaction combined with gel electrophoresis, and then analyzed by direct sequencing in the most common alleles. The results were compared with those in 496 people of Han nationality also live in that district.
Results: There were 19 alleles of the 3'APOB-VNTR in both ethnic groups. They were hypervariable elements (HVEs) 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54, 56, 58, 60, 62 and 64, but HVEs 56 and 58 in Heiyi Zhuang nationality and HVEs 48 and 62 in Han nationality were not be detected. The most common allele is HVE32 in Heiyi and Zhuang nationality (25.9%), and HVE34 in Han nationality (27.2%). The frequencies of HVEs 26, 30, 46, heterozygote, and short alleles (< 38 repeats, S) were higher in Heiyi Zhuang nationality than in Han nationality, whereas the frequencies of HVEs 34, 38, 40, homozygote, and long alleles (>or= 38 repeats, L) were lower in Heiyi Zhuang nationality than in Han nationality. The levels of total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C) and apolipoprotein (apo) B in Heiyi Zhuang nationality were higher in VNTR-LS (carrier of one long and one short alleles) than in VNTR-LL genotypes (the individual carrying two long alleles) genotypes. The levels of TC, triglycerides, HDL-C and apo B in Heiyi Zhuang nationality were also higher in homozygotes than in heterozygotes. There were no significant differences in the detected lipid parameters between the VNTR-SS (carrier of two short alleles) and VNTR-LS or VNTR-LL genotypes in both ethnic groups.
Conclusion: The 3'APOB-VNTR polymorphism is found to be significant difference between Heiyi Zhuang nationality and Han populations, and is associated with the serum lipid levels in Heiyi Zhuang nalionality but not in Han nationality.