Molecular analysis of hereditary nonpolyposis colorectal cancer in the United States

TY - JOUR

T1 - Molecular analysis of hereditary nonpolyposis colorectal cancer in the United States

T2 - High mutation detection rate among clinically selected families and characterization of an American founder genomic deletion of the MSH2 gene

AU - Wagner, Anja

AU - Barrows, Alicia

AU - Wijnen, Juul Th

AU - Van Der Klift, Heleen

AU - Franken, Patrick F.

AU - Verkuijlen, Paul

AU - Nakagawa, Hidewaki

AU - Geugien, Marjan

AU - Jaghmohan-Changur, Shantie

AU - Breukel, Cor

AU - Meijers-Heijboer, Hanne

AU - Morreau, Hans

AU - Van Puijenbroek, Marjo

AU - Burn, John

AU - Coronel, Stephany

AU - Kinarski, Yulia

AU - Okimoto, Ross

AU - Watson, Patrice

AU - Lynch, Jane F.

AU - De La Chapelle, Albert

AU - Lynch, Henry T.

AU - Fodde, Riccardo

PY - 2003/5/1

Y1 - 2003/5/1

N2 - The identification of germline mutations in families with HNPCC is hampered by genetic heterogeneity and clinical variability. In previous studies, MSH2 and MLH1 mutations were found in approximately two-thirds of the Amsterdam-criteria-positive families and in much lower percentages of the Amsterdam-criteria-negative families. Therefore, a considerable proportion of HNPCC seems not to be accounted for by the major mismatch repair (MMR) genes. Does the latter result from a lack of sensitivity of mutation detection techniques, or do additional genes underlie the remaining cases? In this study we address these questions by thoroughly investigating a cohort of clinically selected North American families with HNPCC. We analyzed 59 clinically well-defined U.S. families with HNPCC for MSH2, MLH1, and MSH6 mutations. To maximize mutation detection, different techniques were employed, including denaturing gradient gel electrophoresis, Southern analysis, microsatellite instability, immunohistochemistry, and monoallelic expression analysis. In 45 (92%) of the 49 Amsterdam-criteria-positive families and in 7 (70%) of the 10 Amsterdam-criteria-negative families, a mutation was detected in one of the three analyzed MMR genes. Forty-nine mutations were in MSH2 or MLH1, and only three were in MSH6. A considerable proportion (27%) of the mutations were genomic rearrangements (12 in MSH2 and 2 in MLH1). Notably, a deletion encompassing exons 1-6 of MSH2 was detected in seven apparently unrelated families (12% of the total cohort) and was subsequently proven to be a founder. Screening of a second U.S. cohort with HNPCC from Ohio allowed the identification of two additional kindreds with the identical founder deletion. In the present study, we show that optimal mutation detection in HNPCC is achieved by combining accurate and expert clinical selection with an extensive mutation detection strategy. Notably, we identified a common North American deletion in MSH2, accounting for ∼10% of our cohort. Genealogical, molecular, and haplotype studies showed that this deletion represents a North American founder mutation that could be traced back to the 19th century.

AB - The identification of germline mutations in families with HNPCC is hampered by genetic heterogeneity and clinical variability. In previous studies, MSH2 and MLH1 mutations were found in approximately two-thirds of the Amsterdam-criteria-positive families and in much lower percentages of the Amsterdam-criteria-negative families. Therefore, a considerable proportion of HNPCC seems not to be accounted for by the major mismatch repair (MMR) genes. Does the latter result from a lack of sensitivity of mutation detection techniques, or do additional genes underlie the remaining cases? In this study we address these questions by thoroughly investigating a cohort of clinically selected North American families with HNPCC. We analyzed 59 clinically well-defined U.S. families with HNPCC for MSH2, MLH1, and MSH6 mutations. To maximize mutation detection, different techniques were employed, including denaturing gradient gel electrophoresis, Southern analysis, microsatellite instability, immunohistochemistry, and monoallelic expression analysis. In 45 (92%) of the 49 Amsterdam-criteria-positive families and in 7 (70%) of the 10 Amsterdam-criteria-negative families, a mutation was detected in one of the three analyzed MMR genes. Forty-nine mutations were in MSH2 or MLH1, and only three were in MSH6. A considerable proportion (27%) of the mutations were genomic rearrangements (12 in MSH2 and 2 in MLH1). Notably, a deletion encompassing exons 1-6 of MSH2 was detected in seven apparently unrelated families (12% of the total cohort) and was subsequently proven to be a founder. Screening of a second U.S. cohort with HNPCC from Ohio allowed the identification of two additional kindreds with the identical founder deletion. In the present study, we show that optimal mutation detection in HNPCC is achieved by combining accurate and expert clinical selection with an extensive mutation detection strategy. Notably, we identified a common North American deletion in MSH2, accounting for ∼10% of our cohort. Genealogical, molecular, and haplotype studies showed that this deletion represents a North American founder mutation that could be traced back to the 19th century.

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U2 - 10.1086/373963

DO - 10.1086/373963

M3 - Article

VL - 72

SP - 1088

EP - 1100

JO - American Journal of Human Genetics

JF - American Journal of Human Genetics

SN - 0002-9297

IS - 5

ER -