Abstract
Background: Here we reported a particular case of MUTYH-associated polyposis (MAP) that had only one rare heterozygous mutation, but some particular clinical manifestations contributed to occur in this male patient by only one defective MUTYH allele were worth of further investigation.
Case presentation: We reported a case of MAP. It is about a 33-year-old man with chief complaints of hematochezia who had multiple polyps which were found in his colon via colonoscopy. He followed his doctor’s advice and performed a genetic analysis examination. Germline test was positive for a major heterozygous mutation: chr1:45800165 on the MUTYH gene. MUTYH gene sequence analysis confirmed the following heterozygous mutation: c.55CT (p.R19X) in exon 2 (ClinVar NM_001128425). Unfortunately, his mother and daughter have the ilk mutation according to genetic analysis (Figure 1). However, this mutation at the site was not detected in his father. Various types of polyps were found on repeated colonoscopy, which tended to become latent cancerous in the futre.
Conclusion: This case indicated that awareness of the risk of carcinogenesis of polyps in carriers of monoallelic mutations might accordingly increase and understanding of the type of genetic-related disease will be enhanced by us.
keywords: MUTYH; Colorectal cancer; Hereditary colorectal cancer; Polyposis