纤维蛋白原Bβ基因启动区单核苷酸多态性及连锁不平衡分析

目的　探讨纤维蛋白原 B(fibrinogen,FGB)基因启动区 - 14 8C/ T、- 4 5 5 G/ A、- 85 4 G/ A3个位点单核苷酸多态性 (single nucleotide polymorphism,SNP)在中国南方汉族人群的分布特征及连锁不平衡关系。方法　应用聚合酶链反应 -限制性片段长度多态性技术结合 DNA测序分析检测 377名中国南方汉族人 FGBβ基因型和等位基因的分布频率 ,群体数理遗传学方法分析 FGBβ 3个基因位点 SNP的遗传平衡吻合度和相互间连锁不平衡关系。结果　 3个 FGBβ SNP位点等位基因频率分布符合 Hardy-Weinberg平衡。检出了 FGBβ3个位点 SNP的共 9种基因型 ,- 14 8CC、CT、TT基因型频率分别为0 .5 97、0 .35 8和 0 .0 4 5 ;- 4 5 5 G/ A SNP各基因型频率与 - 14 8C/ T SNP相同 ;- 85 4 GG、GA、AA基因型频率分别为 0 .82 0、0 .178和 0 .0 0 2。各 SNP位点的少见型等位基因频率分别是 0 .2 2 4 (- 14 8T)、0 .2 2 4 (-4 5 5 A)、0 .0 92 (- 85 4 A) ;常见型等位基因频率分别为 0 .776 (- 14 8C)、0 .776 (- 4 5 5 G)、0 .90 8(- 85 4 G)。男女性别间各基因型和等位基因分布频率差异无显著性 (P>0 .0 5 )。经连锁不平衡检验 ,- 14 8C与 - 4 5 5 GSNP为完全一致型 ,- 85 4 G/ A与 - 14 8C/ T、- 4 5 5 G/ A为随机分布。结

Preliminary study on single nucleotide polymorphisms and linkage disequilibrium in promoter region of fibrinogen B beta gene

OBJECTIVE: To investigate the distribution characters and linkage disequilibrium of single nucleotide polymorphisms (SNPs) -148C/T, -455G/A and -854G/A in the promoter region of fibrinogen B(FGB) beta gene. METHODS: Genotype and allele frequencies of FGB beta gene were examined by polymerase chain reaction-restriction fragment length polymorphism and nucleotide sequencing methods in 377 Chinese southern Han individuals. Three FGB beta SNPs Hardy-Weinberg equilibrium and linkage disequilibrium were analyzed with population genetics methods. RESULTS: The allele frequencies of 3 SNPs are in good agreement with Hardy-Weinberg equilibrium. A total of 9 genotypes among the 377 individuals were identified in 3 SNPs. The genotype frequencies of -148CC, CT and TT were 0.597, 0.358 and 0.045, respectively; the -455G/A genotype frequencies were the same as that of -148C/T SNP; the genotype frequencies of -854GG,GA, AA were 0.820,0.178,0.002, respectively. The frequencies of rare allele -148T, -455A and -854A were 0.224,0.224 and 0.092, respectively, while the common allele frequencies were 0.776 for -148C, 0.776 for -455G, and 0.908 for -854G. There were no statistically significant differences in genotype and allele frequencies between the male and female groups (P>0.05). The relationship between -455G and -148C was completely concordant, but there was a random distribution between -854 and -148 (-445) SNPs. CONCLUSION: The results show there is a complete linkage disequilibrium between -148C/T and -455G/A and a negative linkage disequilibrium between -854G/A and -148C/T, as well as between -854G/A and -455G/A. This study has provided population genetics data on FGB beta gene promoter in Chinese southern Han population.