A novel complex mutation in MSH2 contributes to both Muir-Torre and Lynch Syndrome.
Mutations in mismatch repair genes lead to Lynch Syndrome, the most common form of inherited colorectal cancer. In this report, we describe a novel complex germline mutation c.[1601_1661+92dup; 1591_1611del] of the mismatch repair gene, MSH2. This mutation, which segregates with the disease phenotype, was discovered in a Lynch syndrome kindred that also shows a history of the Muir-Torre syndrome. Interestingly, several tumors from this family displayed microsatellite instability, a hallmark of Lynch syndrome tumors but no consistent, concomitant loss of MSH2 protein expression. In addition, a subset of tumors showed neither prototypical feature of microsatellite instability nor immunohistochemistry deficiency, highlighting the importance of a detailed molecular analysis of rare genetic alterations. This mutation and the atypical clinical manifestations observed underscore the genetic complexity underlying Lynch syndrome, and the importance of comprehensive molecular screening in the diagnosis and early detection of colorectal and other associated cancers.
Perera
Sheron
S
Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada.
Ramyar
Lily
L
Mitri
Angie
A
Pollett
Aaron
A
Gallinger
Steven
S
Speevak
Marsha D
MD
Aronson
Melyssa
M
Bapat
Bharati
B
D003123:Colorectal Neoplasms, Hereditary Nonpolyposis / Q000235:genetics* / Q000503:physiopathology; D019295:Computational Biology; D053843:DNA Mismatch Repair; D005190:Family; D005260:Female; D020022:Genetic Predisposition to Disease; D018095:Germ-Line Mutation; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D053842:Microsatellite Instability; D055653:Muir-Torre Syndrome / Q000235:genetics* / Q000503:physiopathology; D051718:MutS Homolog 2 Protein / Q000235:genetics*; D010375:Pedigree
D051718:MutS Homolog 2 Protein