Molecular basis of familial adenomatous polyposis in the southeast of Brazil: identification of six novel mutations

Int J Biol Markers. 2019 Mar;34(1):80-89. doi: 10.1177/1724600818814462. Epub 2019 Mar 11.

Abstract

Background: The goal of this study was to screen point mutations and deletions in APC and MUTYH genes in patients suspected of familial adenomatous polyposis (FAP) in a Brazilian cohort.

Methods: We used high-resolution melting, Sanger direct sequencing and multiplex ligation-dependent probe association (MLPA) assays to identify point mutations, and large genomic variations within the coding regions of APC and MUTYH genes.

Results: We identified 19 causative mutations in 40 Brazilian patients from 20 different families. Four novel mutations were identified in the APC gene and two in the MUTYH gene. We also found a high intra- and inter-familial diversity regarding extracolonic manifestations, and gastric polyps were the most common manifestation found in our cohort.

Conclusion: We believe that the FAP mutational spectrum can be population-specific and screening FAP patients in different populations can improve pre-clinical diagnosis and improve clinical conduct.

Keywords: APC; Familial adenomatous polyposis; HRM technique; MUTYH; admixed population.

MeSH terms

  • Adenomatous Polyposis Coli / genetics*
  • Adenomatous Polyposis Coli / pathology
  • Adenomatous Polyposis Coli Protein / genetics*
  • Adolescent
  • Adult
  • Aged
  • Biomarkers, Tumor / genetics*
  • Brazil / epidemiology
  • Child
  • Child, Preschool
  • DNA Glycosylases / genetics*
  • Female
  • Follow-Up Studies
  • Genetic Predisposition to Disease*
  • Humans
  • Male
  • Middle Aged
  • Mutation*
  • Phenotype
  • Prognosis
  • Young Adult

Substances

  • APC protein, human
  • Adenomatous Polyposis Coli Protein
  • Biomarkers, Tumor
  • DNA Glycosylases
  • mutY adenine glycosylase