MUTYH-associated polyposis

Genetics

• Autosomal recessive, MUTYH gene on chromosome 1p

Clinical

• Usually develop between 10 to 100 colorectal polyps by the fifth or sixth decade
  • Can have >100
• Other manifestations:
  • Duodenal adenomas – but less of a problem than in FAP
  • Extra-colonic manifestations are not well defined
    • May include
      • Osteomas and dental cysts
      • Congenital hypertrophy of the retinal pigment epithelium,
      • Dental cysts
      • Desmoids
      • Sebaceous hyperplasia
      • Muir-Torre phenotype with sebaceous gland tumors

Management

• Similar to FAP, annual colonoscopy can be started slightly later froma ge 20
• Gastroscopy from age 35.