穿孔素基因多态性与儿童噬血细胞综合征的相关性研究

Association between gene polymorphisms of Perforin 1 and hemophagocytic lymphohistiocytosis

摘要:

目的 了解穿孔素基因(PRF1)多态性在噬血细胞综合征(HLH)患儿中的分布情况,探讨PRF1 基因多态性与HLH 是否存在易感相关性。方法 收集2009 年1 月至2013 年12 月确诊为HLH的48 例患儿(HLH 组)及100 名健康体检儿童(对照组)的临床资料,应用聚合酶链反应(PCR)结合直接测序方法对两组患儿的PRF1 基因编码区(包括3 个外显子和2 个内含子)进行基因多态性位点筛查。结果 48 例HLH 患儿中,在PRF1 基因编码序列中共发现3 个SNP 位点,而在非编码序列中共发现7 个SNP 位点;PRF1 基因非编码序列中还有2 个SNP 位点rs10999426 和rs10999427 分别仅在5 例对照组儿童中发现(5%);以上12 个SNP 位点在HLH 组和对照组中的基因型及等位基因频率分布差异均无统计学意义(P>0.05)。连锁不平衡分析提示rs10999426 和rs10999427 紧密连锁(D=1,r²=1),但上述2 个位点构建的A-T 单体型在HLH组和对照组中的分布频率差异无统计学意义(P>0.05)。结论 PRF1 基因多态性与HLH 发病存在易感相关性的可能性不大;rs10999426 和rs10999427 存在连锁不平衡关系,其构建的A-T 单体型虽仅在对照组中发现,但发生率低,可能不是家族性HLH 的保护性因素。

Abstract:

Objective To investigate frequency distribution of gene polymorphisms of PRF1 gene in children with hemophagocytic lymphohistiocytosis (HLH), and to explore whether the possible gene polymorphisms of PRF1 gene confer an increased risk of susceptibility to HLH. Methods Forty-eight children who were diagnosed with HLH between January 2009 and December 2013 (HLH group) and 100 healthy children (control group) were enrolled in this study. The gene polymorphisms in the coding region of PRF1 gene, which consists of three exons and two introns, were genotyped by PCR, followed by direct sequencing. Results Three single nucleotide polymorphisms (SNPs) were revealed in the coding sequence of PRF1 in the 48 children with HLH. Seven SNPs were detected in the noncoding sequence. Other two SNPs in the noncoding sequence including rs10999426 and rs10999427 were detected only in 5 healthy children (5%). There was no significant difference in allelic frequencies of all the SNPs above between the HLH and control groups (P>0.05). Haplotype analysis showed there was a pair-wise linkage disequilibrium between rs10999426 and rs10999427 (D=1, r²=1), but there was no significant difference in the distribution of A-T haplotype between the HLH and control groups (P>0.05). Conclusions There is no association between gene polymorphisms of PRF1 gene and the susceptibility to HLH. There is a pair-wise linkage disequilibrium between rs10999426 and rs10999427, but a low detection rate of A-T haplotype in healthy children indicates that it might not play a protective role in the development of HLH.