目的:对1个家族性腺瘤性息肉病家系成员进行基因变异分析，明确其可能的致病原因。方法:应用二代测序技术对先证者进行基因检测，应用Sanger测序对先证者及家系成员进行变异验证。结果:先证者及其母亲和哥哥n APC基因存在c.532-1G>A杂合变异，该变异为剪接位点变异，会导致n APC基因mRNA的异常剪接，造成APC蛋白截短，影响正常功能发挥，促进肿瘤发生。根据美国医学遗传学与基因组学学会遗传变异分类标准与指南，n APC基因c.532-1G>A变异判定为致病性变异(PVS1+PP1+PP4+PP5)。n 结论:APC基因c.532-1G>A变异可能是本家系家族性腺瘤性息肉病的遗传学病因。n “,”Objective:To explore the genetic basis for a pedigree affected with familial adenomatous polyposis (FAP).Methods:The proband, with recurrence of blood in the stool, was diagnosed with FAP by endoscopy, pathological examination and a family history. She was subjected to next generation sequencing to detect genetic variant. Suspected variant was verified by Sanger sequencing of members from her pedigree.Results:The proband, her mother and brother were found to carry a heterozygous c. 532-1G>A variant of then APC gene, which may lead to aberrant splicing of mRNA resulting in a truncated protein, which may lose its normal function and promote the tumorigenesis. Based on the American College of Medical Genetics and Genomics standards and guidelines, c. 532-1G>A variant ofn APC gene was predicted to be pathogenic(PVS1+ PP1+ PP4+ PP5).n Conclusion:The c. 532-1G>A variant of then APC gene probably underlay the pathogenesis of FAP in this pedigree.n