利用二代测序数据探索SPRY基因家族与中国人群非综合征型唇腭裂的关联

Exploring the association between SPRY gene family and non-syndromic oral clefts among Chinese populations using data of a next-generation sequencing study

目的:探索 SPRY 基因家族中的单核苷酸多态性及亲源效应与中国人群非综合征型唇腭裂发病风险的关联。方法:研究基于病例-双亲设计,以2016—2018年于北京大学口腔医院募集的 183个中国人群非综合征型唇裂合并或不合并腭裂(non-syndromic cleft lip with or without cleft palate,NSCL/P)核心家系(549人)为研究对象。利用其二代测序数据中的 SPRY 基因家族相关信息,展开单核苷酸多态性和亲源效应分析。该测序研究采用二阶段设计,第一阶段对24个家系进行全外显子组测序探索潜在阳性信号,第二阶段在159个家系的独立样本中对第一阶段结果进行验证。采用问卷调查收集NSCL/P患者及其父母的基本情况、患病情况、临床特征及孕期环境暴露等信息。收集患儿及其父母的血液并提取DNA进行基因检测以获取遗传信息。单核苷酸多态性分析采用传递不平衡检验,亲源效应分析采用 Z 检验,统计分析使用PLINK(v1.07)软件完成。第一阶段的多位点分析采用以家系为基础的序列核心关联检验方法,由R软件(v3.5.1)famSKAT-RC包完成。采用Bonferroni法对验证结果进行多重检验校正。结果:经过质量控制,第一阶段共有22个 SPRY 基因家族的位点纳入分析,结合位点的注释、功能预测结果及统计检验结果,纳入rs1298215244 ( SPRY1 )和rs504122 ( SPRY2 )两个位点进入二阶段验证。二阶段传递不平衡检验发现,rs1298215244: T>C、rs504122: G>C两种常见变异以及rs504122: G>T罕见变异与NSCL/P的关联达到Bonferroni多重检验校正后的显著性水平,位于 SPRY1 的rs1298215244: T>C其亲源效应矫正前具有统计学意义,但未能通过多重检验校正。结论:发现 SPRY 基因家族中的单核苷酸多态性与中国人群NSCL/P的发病风险存在关联,但未发现 SPRY 基因家族具有亲源效应。

Objective: To explore the association between SPRY gene family and the risk of non-syndromic oral clefts among Chinese populations, in respect of single nucleotide polymorphisms (SNPs) association and parent-of-origin effects. Methods: Based on case-parent design, this study used the data of SPRY gene family in a next generation sequencing study of 183 non-syndromic cleft lip with or without cleft palate (NSCL/P) case-parent trios (549 participants) recruited from 2016 to 2018, to analyze the effects of SNP association and parent-of-origin. The sequencing study adopted a two-stage design. In the first stage, whole exome sequencing was conducted among 24 NSCL/P trios with family history to explore potential signals. Then in the second stage, another 159 NSCL/P trios were used as validation samples to verify the signals found in the first stage. The data of general information, disease features and parental environmental exposures for participants were collected through questionnaires. Blood samples were collected from each participant for DNA extraction and sequencing. Transmission disequilibrium tests (TDT) were conducted to test for the association between SNPs and NSCL/P, while Z score tests were applied to analyze parent-of-origin effects. The analyses were performed using Plink (v1.07). TRIO package in R (v3.5.1). Besides, famSKAT analyses were conducted in the first stage to combine the effect of SNPs located on the same gene, using famSKAT package in R(V3.5.1). Bonferroni method was adopted to correct multiple tests in the second stage. Results: Twenty-two SNPs in SPRY gene family were included for analyses after the quality control process in the first stage. Based on the variants annotation, functional prediction and statistical analysis, rs1298215244 ( SPRY1 ) and rs504122 ( SPRY2 ) were included in the second verification stage. TDTs in the verification stage revealed that rs1298215244: T>C, rs504122: G>C and rs504122: G>T were associated with the risk of NSCL/P after Bonferroni corrections, where rs504122: G>T was a rare variation. Although the test for parent-of-origin effect of rs1298215244: T>C reached nominal significance level, no SNP showed significant association with NSCL/P through parent-of-origin effect after Bonferroni corrections. Conclusion: This study found that SNPs (including both common and rare variants) among the SPRY gene family were associated with the risk of NSCL/P among Chinese populations. This study failed to detect parent-of-origin effects among the SPRY gene family.