Liver & GIT
Which is false FAP (AIIMS May 2010)
|A||It is autosomal recessive|
|B||Polyps develop in late adulthood|
|C||Screened by sigmoidoscopy|
|D||Polyps found in colon|
Familial adenomatous polyposis (FAP) (H-18th Pg- 769)
Signs and symptoms
1. These may bleed, leading to blood in the stool. Develop anemia due to gradually developing iron deficiency.
4. Other signs that may point to FAP are pigmented lesions of the retina ("CHRPE - congenital hypertrophy of the retinal pigment epithelium"), jaw cysts, sebaceous cysts, and osteomata (benign bone tumors).
Diagnosis and treatment
1. Barium enema
2. Colonoscopy is considered the diagnostic test of choice
Once the diagnosis of FAP is made, close colonoscopic surveillance with polypectomy is required. Prophylactic colectomy is indicated if more than a hundred polyps are present, if there are severely dysplastic polyps, or if multiple polyps larger than 1 cm are present.
a. Familial adenomatous polyposis can have different inheritance patterns and different genetic causes.
c. The incidence of malignancy in these cases approaches 100%. In most cases, an affected person has one parent with the condition.
d. Mutations in the MUTYH gene are inherited in an autosomal recessive pattern
a. Treatment for FAP depends on the genotype. Most individuals with the APC mutation will develop colon cancer by the age of 40. Therefore, prophylactic surgery is generally recommended before the age of 25.
b. If the rectum has few polyps, the colon is removed and the (ileum) is connected to the rectum (ileorectal anastomosis).
d. The NSAIDS have been shown to significantly decrease the number of polyps but do not usually alter management since there are still too many polyps to be followed and treated endoscopically.