FAP - familial adenomatous polyposis germline mutations in the APC gene

(“gatekeeper”)

HNPCC - hereditary nonpolyposis colon cancer (a.k.a. Lynch syndrome)

germline mutations in DNA mismatch repair genes (“caretaker”)

autosomal dominant loss of heterozygosity

mutS homolog 2, colon cancer, nonpolyposis type 1 (E. coli)

maps to human chromosome 2p22-21

heterozygous for mismatch repair genes hMSH2 and hMLH1 = tumor suppressors

Black = +/+ Green = G674A/+

solid red = G674A/G674A

blue = -/- Dotted red =

backcross

the HALMARK of Lynch Syndrome (HNPCC)

Defective MMR = MSI

5 standard DNA markers: *BAT26*

surgical management – partial colectomy

chemotherapy – need functional MMR

possible preventative treatment› aspirin› resistant starch (fiber)