MUTYH-associated polyposis

MUTYH-associated polyposis 

Updated: 03/02/2021

© Jun Wang, MD, PhD

General features

• AKA MYH-associated polyposis
  
• Autosomal recessive
• Considered a mild form of familial adenomatous polyposis
  
• Biallelic mutation of MUTYH gene (DNA mismatch repair)
• Less 1% of patients with colorectal cancer
  

Pathogenesis

• MUTYH mutation results in mutation of other genes, including APC and KRAS
  

Clinical presentations

• Multiple colon polyps, usually less than 100, by age 50 to 60
  
• Extracolonic presentations
• Polyps may be seen in other organs, such as stomach and small intestine
• Osteoma
• Sebaceous hyperplasia or adenoma, etc
  

Pathological features

• Primarily adenoma
• Severe dysplasia at early age

Genetic abnormalities

• MUTYH
  

Diagnosis

• Suspicious presentations
• Cumulative 10 or more colorectal adenomas
• Colorectal adenoma with extracolic features of FAP
  
• Genetic testing for MYH
  

Back to intestinal tumors
Back to syndromes
Back to contents