TY - JOUR
T1 - An American founder mutation in MLH1
AU - Tomsic, Jerneja
AU - Liyanarachchi, Sandya
AU - Hampel, Heather
AU - Morak, Monika
AU - Thomas, Brittany C.
AU - Raymond, Victoria M.
AU - Chittenden, Anu
AU - Schackert, Hans K.
AU - Gruber, Stephen B.
AU - Syngal, Sapna
AU - Viel, Alessandra
AU - Holinski-Feder, Elke
AU - Thibodeau, Stephen N.
AU - De La Chapelle, Albert
PY - 2012/5/1
Y1 - 2012/5/1
N2 - Mutations in the mismatch repair genes cause Lynch syndrome (LS), conferring high risk of colorectal, endometrial and some other cancers. After the same splice site mutation in the MLH1 gene (c.589-2A>G) had been observed in four ostensibly unrelated American families with typical LS cancers, its occurrence in comprehensive series of LS cases (Mayo Clinic, Germany and Italy) was determined. It occurred in 10 out of 995 LS mutation carriers (1.0%) diagnosed in the Mayo Clinic diagnostic laboratory. It did not occur among 1,803 cases tested for MLH1 mutations by the German HNPCC consortium, while it occurred in three probands and an additional five family members diagnosed in Italy. In the U.S., the splice site mutation occurs on a large (â̂4.8 Mb) shared haplotype that also harbors the variant c.2146G>A, which predicts a missense change in codon 716 referred to here as V716M. In Italy, it occurs on a different, shorter shared haplotype (â̂2.2 Mb) that does not carry V716M. The V716M variant was found to be present by itself in the U.S., German and Italian populations with individuals sharing a common haplotype of 280 kb, allowing us to calculate that the variant arose around 5,600 years ago (225 generations; 95% confidence interval 183-272). The splice site mutation in America arose or was introduced some 450 years ago (18 generations; 95% confidence interval 14-23); it accounts for 1.0% all LS in the Unites States and can be readily screened for.
AB - Mutations in the mismatch repair genes cause Lynch syndrome (LS), conferring high risk of colorectal, endometrial and some other cancers. After the same splice site mutation in the MLH1 gene (c.589-2A>G) had been observed in four ostensibly unrelated American families with typical LS cancers, its occurrence in comprehensive series of LS cases (Mayo Clinic, Germany and Italy) was determined. It occurred in 10 out of 995 LS mutation carriers (1.0%) diagnosed in the Mayo Clinic diagnostic laboratory. It did not occur among 1,803 cases tested for MLH1 mutations by the German HNPCC consortium, while it occurred in three probands and an additional five family members diagnosed in Italy. In the U.S., the splice site mutation occurs on a large (â̂4.8 Mb) shared haplotype that also harbors the variant c.2146G>A, which predicts a missense change in codon 716 referred to here as V716M. In Italy, it occurs on a different, shorter shared haplotype (â̂2.2 Mb) that does not carry V716M. The V716M variant was found to be present by itself in the U.S., German and Italian populations with individuals sharing a common haplotype of 280 kb, allowing us to calculate that the variant arose around 5,600 years ago (225 generations; 95% confidence interval 183-272). The splice site mutation in America arose or was introduced some 450 years ago (18 generations; 95% confidence interval 14-23); it accounts for 1.0% all LS in the Unites States and can be readily screened for.
KW - MLH1
KW - colon cancer
KW - founder mutation
KW - genetic predisposition
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U2 - 10.1002/ijc.26233
DO - 10.1002/ijc.26233
M3 - Article
C2 - 21671475
AN - SCOPUS:84857505188
SN - 0020-7136
VL - 130
SP - 2088
EP - 2095
JO - International Journal of Cancer
JF - International Journal of Cancer
IS - 9
ER -