Objective: To investigate the presence of Cosmc gene mutation in children with Henoch-Schönlein purpura (HSP) and the association between Cosmc gene mutation and the susceptibility to HSP.
Mesults: Eighty-four children who were diagnosed with HSP between March 2014 and December 2015 were selected as the HSP group. Fifty-eight healthy volunteers matched for age and sex were enrolled as the control group. Fasting venous blood (5 mL) from the two groups was collected in EDTA anticoagulated tubes, followed by the isolation of peripheral blood mononuclear cells (PBMCs) through density gradient centrifugation. Genomic DNA was extracted from PBMCs according to the manufacturer's protocol, and the whole exon region of Cosmc gene was amplified by touch-down polymerase chain reaction (touch-down PCR). The PCR products were identified by 1% agarose gel and sequenced in order to further examine the association between Cosmc gene mutation and the susceptibility to HSP.
Results: Sequencing results showed two mutations (c.393T>A and c.72A>G) of Cosmc gene in children with HSP. There were no significant differences in the genotype and allele frequencies at the two loci between the HSP and control groups, and this distribution was not associated with sex.
Conclusions: The mutations c.393T>A and c.72A>G in the exon region of Cosmc gene in children with HSP are not associated with the onset of HSP.
目的: 探索过敏性紫癜（HSP）患儿中是否存在Cosmc基因突变以及该突变与HSP发病的关联性。
方法: 选取2014年3月至2015年12月确诊为HSP患儿84例为HSP组，另选取性别和年龄匹配的健康体检者58例为健康对照组。采集两组儿童空腹静脉血5 mL，EDTA抗凝，根据密度梯度离心法分离得到外周血单个核细胞（PBMC），提取PBMC中的基因组DNA，应用降落聚合酶链反应（Touch-down PCR）扩增Cosmc基因全外显子片段，经1%琼脂糖凝胶电泳鉴定后行测序分析，并进一步分析突变与HSP易感性的关系。
结果: 测序结果显示HSP患儿Cosmc基因存在两个位点的突变，分别为c.393T>A和c.72A>G。c.393T>A和c.72A>G突变位点中各基因型、等位基因在两组间比较差异均无统计学意义，且不受性别影响（均P > 0.05）。
结论: HSP患儿Cosmc基因外显子中存在两个突变位点，且与HSP的发病并无关联。