染色体9p21-22区域两个新的SNPs位点在湖南汉族人群中的多态分布

目的 在人类染色体9p21—22区域克隆的两个候选抑瘤基因NGX6和UBAPl以及该区域另一个已知抑瘤基因CDKN2A中筛查未知的单核苷酸多态(single nucleotide polymorphisms，SNPs)。方法 用96名正常人外周血白细胞基因组DNA在3个基因的外显子及基因上下游调控区中逐段PCR扩增、大规模涵序。结果 在UBAP1基因第6外显子及CDKN2A基因第4外显子中各发现一个新的SNP位点，dbSNP登录号为rs3135929和rs3088440，其多态信息含量分别为0．102和0．213。两个SNPs之间不存在连锁不平衡，单倍型分析表明两个SNPs联用，其多态信息含量可达到0．302。结论多 个SNP联用，其多态信息含量明显提高，可克服SNPs信息量不足的弱点；两个SNPs均位于基因的3'非翻译区，对基因表达调控是否有影响值得进一步研究。

Polymorphism of two novel SNPs, which locate on chromosome 9p21-22, in Han Chinese of Hunan

Objective To search novel SNPs in exons and regulatory regions of CDKN2A and two novel putative tumor suppressor genes NGX6 and UBAP1, which all reside on chromosome 9p21 22. Methods The exons and regulatory regions of those genes were amplified and sequenced in 96 subjects. Results Two novel SNPs were found, one resides on the sixth exon of UBAP1 gene and the other on the fourth exon of CDKN2A gene. Two novel SNPs were submitted to the dbSNP database, and their access ID are rs3135929 and rs3088440. The polymorphic information contents of them are 0.102 and 0.213 respectively. There is linkage equilibrium between them, and the polymorphic information content of their haplotype is 0.302, higher than any of them individually. Conclusion The polymophic information content can be improved by using haplotype analysis of several SNPs.