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