先天上颌尖牙缺失家系的致病基因的研究

Identification of pathogenic genes in a canine agenesis family

目的应用全基因组外显子测序技术探究上颌尖牙先天缺失的致病基因。方法本研究的对象为一上颌尖牙先天缺失的家系,该家系由两名上颌尖牙缺失患者和一名健康成员构成。对该家系成员进行血液样本采集及DNA提取。通过全基因组外显子测序技术及生物信息学分析方法筛选该家系可能的致病基因。结合Sanger测序的方法对筛选出的致病突变进行验证。并对验证后的基因进行功能预测及突变位点氨基酸保守性分析。结果通过全基因组外显子测序发现此家系的两名上颌尖牙缺失的患者在ITGAV基因上存在c.C2381G的突变,而在该家系的健康成员中并未发现此突变。此突变为错义突变导致了脯氨酸变成了精氨酸。Sanger测序也证实此突变在该家系中符合疾病共分离。生物信息学分析显示ITGAV在牙胚中有表达。且突变位置的脯氨酸在各物种间具有高度保守性。结论研究结果提示ITGAV可能是导致该家系上颌尖牙缺失的致病基因。

Objective To explore the pathogenic or susceptibility genes for maxillary canine agenesis by whole exome sequencing(WES).Methods The study was performed on a Chinese canine agenesis family which consisted of two maxillary canine agenesis patients and a healthy person.The peripheral blood was collected and genomic DNA was extracted.Then WES was performed on the family.Likely pathogenic variants were filtered out by bioinformatic analysis.Then PCR-Sanger sequencing was performed in all of the family members for verification of the candidate variants.The function of the candidate gene was predicted and the conservation analysis of the mutated amino acid was performed by bioinformatic analysis.Results ITGAV(c.C2381 G)was filtered out in two patients but not in the healthy person.This missense mutation made Proline(Pro)change into Arginine(Arg).Then Sanger sequencing identified that the mutation was co-separated in this family.Bioinformatic analysis showed that the ITGAV expressed in tooth germ.Besides,the Proline in mutated site was highly conserved in different species.Conclusion The study shows that ITGAV may be the pathogenic gene for maxillary canine agenesis.