Cancer data from 1980 to 2007 were obtained from the Familial Gastrointestinal Cancer Registry in Toronto for 321 persons with known MMR mutations: mutL homolog 1, colon cancer, nonpolyposis type 2 (E. coli) (MLH1); mutS homolog 2, colon cancer, nonpolyposis type 1 (E. coli) (MSH2); mutS homolog 6 (E. coli) (MSH6); and PMS2 postmeiotic segregation increased 2 (S. cerevisiae) (PMS2).
Forty-three women with HNPCC were counseled through a gastrointestinal cancer risk program, and later sent a questionnaire regarding their screening practices for gynecologic neoplasms.
The c.1168C>T (p.Leu390Phe), c.1255C>A (p.Gln419Lys), and c.1261C>A (p.Leu421Met) in exon 7 and c.518T>G (p.Leu173Arg) in exon 3 of MSH2 were suspected as predisposing to gastrointestinal cancer.
Ongoing studies at the Hereditary Gastrointestinal Cancer Registry in Hong Kong have revealed a unique germline MSH2c.1452-1455delAATG mutation that has not been reported in other ethnic groups.