[Analysis of APC gene variants in a pedigree affected with familial adenomatous polyposis].

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 the 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 of APC gene was predicted to be pathogenic(PVS1+PP1+PP4+PP5).

CONCLUSION

The c.532-1G>A variant of the APC gene probably underlay the pathogenesis of FAP in this pedigree.