title: Identification of MSH2 inversion of exons 1-7 in clinical evaluation of families with suspected Lynch syndrome.
abstract: Traditional germline sequencing and deletion/duplication analysis does not detect Lynch syndrome-causing mutations in all individuals whose colorectal or endometrial tumors demonstrate mismatch repair (MMR) deficiency. Unique inversions and other rearrangements of the MMR genes have been reported in families with Lynch syndrome. In 2014, a recurrent inversion of MSH2 exons 1-7 was identified in five families suspected to have Lynch syndrome. We aimed to describe our clinical experience in identifying families with this specific inversion. Four probands whose Lynch syndrome-associated tumors demonstrated absence of MSH2/MSH6 staining and who had negative MMR germline testing were evaluated for the MSH2 inversion of exons 1-7, offered during initial genetic workup or upon routine clinical follow-up. All four probands tested positive for the MSH2 inversion. Proband cancer diagnoses included colon and endometrial adenocarcinoma and sebaceous adenoma. A variety of Lynch syndrome-associated cancers were reported in the family histories, although only one family met Amsterdam II criteria. Thirteen at-risk relatives underwent predictive testing. MSH2 inversion of exons 1-7 was found in four probands previously suspected to have Lynch syndrome based on family history and tumor testing. This testing should be offered routinely to patients with tumors demonstrating loss of MSH2/MSH6 staining.
authors.affiliation: Clinical Cancer Genetics Program, UT MD Anderson Center, Unit 1354, 1155 Pressler St., Houston, TX, 77030, USA.
authors.forename: Maureen E
authors.initials: ME
authors.lastname: Mork
authors.affiliation: Department of Clinical Cancer Prevention, UT MD Anderson Cancer Center, Unit 1360, P.O. Box 301439, Houston, TX, 77230-1439, USA.
authors.forename: Andrea
authors.initials: A
authors.lastname: Rodriguez
authors.affiliation: Department of Pathology, UT MD Anderson Cancer Center, Unit 0085, 1515 Holcombe Blvd., Houston, TX, 77030, USA.
authors.forename: Melissa W
authors.initials: MW
authors.lastname: Taggart
authors.affiliation: Clinical Cancer Genetics Program, UT MD Anderson Center, Unit 1354, 1155 Pressler St., Houston, TX, 77030, USA.|Department of Surgical Oncology, UT MD Anderson Cancer Center, Unit 1484, 1400 Pressler St., Houston, TX, 77030, USA.
authors.forename: Miguel A
authors.initials: MA
authors.lastname: Rodriguez-Bigas
authors.affiliation: Clinical Cancer Genetics Program, UT MD Anderson Center, Unit 1354, 1155 Pressler St., Houston, TX, 77030, USA.|Department of Gastroenterology, Hepatology, and Nutrition, UT MD Anderson Cancer Center, Unit 1466, 1515 Holcombe Blvd., Houston, TX, 77030, USA.
authors.forename: Patrick M
authors.initials: PM
authors.lastname: Lynch
authors.affiliation: Clinical Cancer Genetics Program, UT MD Anderson Center, Unit 1354, 1155 Pressler St., Houston, TX, 77030, USA.
authors.forename: Sarah A
authors.initials: SA
authors.lastname: Bannon
authors.affiliation: Clinical Cancer Genetics Program, UT MD Anderson Center, Unit 1354, 1155 Pressler St., Houston, TX, 77030, USA.|Department of Surgical Oncology, UT MD Anderson Cancer Center, Unit 1484, 1400 Pressler St., Houston, TX, 77030, USA.
authors.forename: Y Nancy
authors.initials: YN
authors.lastname: You
authors.affiliation: Clinical Cancer Genetics Program, UT MD Anderson Center, Unit 1354, 1155 Pressler St., Houston, TX, 77030, USA. evilar@mdanderson.org.|Department of Clinical Cancer Prevention, UT MD Anderson Cancer Center, Unit 1360, P.O. Box 301439, Houston, TX, 77230-1439, USA. evilar@mdanderson.org.|Department of Gastrointestinal Medical Oncology, UT MD Anderson Center, Unit 426, 1515 Holcombe Blvd., Houston, TX, 77030, USA. evilar@mdanderson.org.
authors.forename: Eduardo
authors.initials: E
authors.lastname: Vilar
mesh_terms: D000328:Adult; D003123:Colorectal Neoplasms, Hereditary Nonpolyposis / Q000235:genetics*; D005091:Exons / Q000235:genetics; D005260:Female; D015321:Gene Rearrangement / Q000235:genetics; D006801:Humans; D008297:Male; D008875:Middle Aged; D051718:MutS Homolog 2 Protein / Q000235:genetics*; D010375:Pedigree
chemical_list: C497172:MSH2 protein, human; D051718:MutS Homolog 2 Protein
keywords: Lynch syndrome; MSH2 inversion; Mismatch repair