Identification of Patients with (Atypical) MUTYH-Associated Polyposis by KRAS2 c.34G > T Prescreening Followed by MUTYH Hotspot Analysis in Formalin-Fixed Paraffin-Embedded Tissue

Purpose: To assess the feasibility of identifying patients with (atypical) MUTYH-associated polyposis (MAP) by KRAS2 c.34G > T prescreening followed by MUTYH hotspot mutation analysis in formalin-fixed paraffin-embedded tissue (FFPE). Methods: We collected 210 colorectal FFPE tumors from 192 individuals who presented with <10 adenomas or familial mismatch repair proficient colorectal carcinomas with <10 concomitant adenomas. The tissues were tested for somatic KRAS2 mutations and for three Dutch hotspot MUTYH germ line mutations (p.Tyr165Cys, p.Gly382Asp, and p.Pro391Leu) by sequencing analysis. Results: The c.34G > T, KRAS2 transversion was detected in 10 of 210 tumors. In one of these 10 cases, a monoallelic p.Gly382Asp MUTYH mutation was found and a full MUTYH analysis in leukocyte DNA revealed an unclassified variant p.Met269Val. This was in a 61-year-old patient with a cecum carcinoma and three adenomas. After further requests, her family case history revealed that her brother had had between 10 and 15 adenomas and turned out to carry both MUTYH germ line mutations. MUTYH hotspot mutation screening in 182 patients without the somatic c.34G > T KRAS2 mutation led to the detection of three monoallelic germ line MUTYH mutation carriers. Conclusion:KRAS2 c.34G > T somatic prescreening, followed by MUTYH hotspot mutation analysis when positive, can identify patients with (atypical) MAP. If heterozygous hotspot MUTYH mutations are identified, a complete germ line MUTYH mutation screening should be carried out if possible. Immediate MUTYH hotspot mutation analysis is a practical alternative in patients with >10 adenomas or in cases of multiple colorectal carcinomas in one generation for which only FFPE tissue is available.

[1]  J. Cheadle,et al.  MUTYH-associated polyposis--from defect in base excision repair to clinical genetic testing. , 2007, DNA repair.

[2]  F. Guillemot,et al.  Low frequency of AXIN2 mutations and high frequency of MUTYH mutations in patients with multiple polyposis , 2006, Human mutation.

[3]  E. Kuipers,et al.  Duodenal carcinoma in MUTYH-associated polyposis , 2006, Journal of Clinical Pathology.

[4]  P. Propping,et al.  MUTYH‐associated polyposis: 70 of 71 patients with biallelic mutations present with an attenuated or atypical phenotype , 2006, International journal of cancer.

[5]  E. Kuipers,et al.  Multiplicity in polyp count and extracolonic manifestations in 40 Dutch patients with MYH associated polyposis coli (MAP) , 2005, Journal of Medical Genetics.

[6]  J. Prendergast,et al.  Germline susceptibility to colorectal cancer due to base-excision repair gene defects. , 2005, American journal of human genetics.

[7]  A. Tenesa,et al.  Re: Association between biallelic and monoallelic germline MYH gene mutations and colorectal cancer risk. , 2005, Journal of the National Cancer Institute.

[8]  A. Brehm,et al.  Germline MUTYH (MYH) mutations in Portuguese individuals with multiple colorectal adenomas , 2004, Human mutation.

[9]  K. Hardy,et al.  Identification of novel and rare mutations in California Hispanic and African American cystic fibrosis patients , 2004, Human mutation.

[10]  P. Radice,et al.  Prevalence of the Y165C, G382D and 1395delGGA germline mutations of the MYH gene in Italian patients with adenomatous polyposis coli and colorectal adenomas , 2004, International journal of cancer.

[11]  G. Williams,et al.  Increased frequency of the k-ras G12C mutation in MYH polyposis colorectal adenomas , 2004, British Journal of Cancer.

[12]  H. Meijers-Heijboer,et al.  Microsatellite Instability, Immunohistochemistry, and Additional PMS2 Staining in Suspected Hereditary Nonpolyposis Colorectal Cancer , 2004, Clinical Cancer Research.

[13]  L. Lipton,et al.  Carcinogenesis in MYH-associated polyposis follows a distinct genetic pathway. , 2003, Cancer research.

[14]  Siân Jones,et al.  Autosomal recessive colorectal adenomatous polyposis due to inherited mutations of MYH , 2003, The Lancet.

[15]  L. Lipton,et al.  Multiple colorectal adenomas, classic adenomatous polyposis, and germ-line mutations in MYH. , 2003, The New England journal of medicine.

[16]  Siân Jones,et al.  Biallelic germline mutations in MYH predispose to multiple colorectal adenoma and somatic G:C-->T:A mutations. , 2002, Human molecular genetics.

[17]  Alison L. Livingston,et al.  Inherited variants of MYH associated with somatic G:C→T:A mutations in colorectal tumors , 2002, Nature Genetics.

[18]  A. Norman,et al.  Kirsten ras mutations in patients with colorectal cancer: the multicenter "RASCAL" study. , 1998, Journal of the National Cancer Institute.

[19]  J. Knight,et al.  Association between biallelic and monoallelic germline MYH gene mutations and colorectal cancer risk. , 2004, Journal of the National Cancer Institute.