Relative role of APC and MUTYH mutations in the pathogenesis of familial adenomatous polyposis

Annalisa Pezzi, Luca Roncucci, Piero Benatti, Romano Sassatelli, Liliana Varesco, Carmela Di Gregorio, Tiziana Venesio, Monica Pedroni, Stefania Maffei, Luca Reggiani Bonetti, Enrica Borsi, Maurizio Ferrari, Pietro Martella, Giuseppina Rossi, Maurizio Ponz De Leon

Research output: Contribution to journalArticlepeer-review


Objective. Familial adenomatous polyposis (FAP) is an interesting model for the study of colorectal tumour. Two genes contribute to the FAP phenotype APC and MUTYH but their relative role is still undefined. The objective of this study was to evaluate the contribution of the two genes to the pathogenesis of FAP by means of a series of FAP families. Material and methods. Sixty-one unrelated families with a diagnosis of FAP and a total of 187 affected individuals were evaluated. After extracting DNA, APC and MUTYH genes were sequenced. Results. In the whole series of patients, colectomy with ileorectal anastomosis was the most frequent surgery, although the number of patients treated by total proctocolectomy and ileoanal anastomosis was increasing. Duodenal and jejunal-ileal adenomas were present in more than half of the patients. Constitutional mutations were detected in 37 of the 45 families (82.2%); there were 33 families with APC and 4 with MUTYH alterations. Age at onset of polyposis and age at surgery were 1015 years delayed for carriers of MUTYH mutations; cancer at diagnosis was frequent, and extracolonic manifestations were diagnosed in the majority of MUTYH-positive families. MUTYH-associated polyposis showed the horizontal transmission expected for recessive inheritance (at variance with the dominant pattern seen with APC mutations). Conclusions. At least two genes are associated with the FAP phenotype. APC mutations account for the majority of cases, while MUTYH mutations can be observed in 10% of patients. There are few but definite differences between APC- and MUTYH-associated FAP, such as age at diagnosis and pattern of transmission.

Original languageEnglish
Pages (from-to)1092-1100
Number of pages9
JournalScandinavian Journal of Gastroenterology
Issue number9
Publication statusPublished - 2009


  • Adenoma
  • APC
  • Cancer
  • FAP
  • Polyp

ASJC Scopus subject areas

  • Gastroenterology


Dive into the research topics of 'Relative role of APC and MUTYH mutations in the pathogenesis of familial adenomatous polyposis'. Together they form a unique fingerprint.

Cite this