Comprehensive Constitutional Genetic and Epigenetic Characterization of Lynch-Like Individuals

The causal mechanism for cancer predisposition in Lynch-like syndrome (LLS) remains unknown. Our aim was to elucidate the constitutional basis of mismatch repair (MMR) deficiency in LLS patients throughout a comprehensive (epi)genetic analysis. One hundred and fifteen LLS patients harboring MMR-defi...

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Detalles Bibliográficos
Autores: Damaso, E, Gonzalez-Acosta, M, Vargas-Parra, G, Navarro, M, Balmana, J, Cajal, TRY, Tuset, N, Thompson, BA, Marin, F, Fernandez, A, Gomez, C, Velasco, A, Solanes, A, Iglesias, S, Urgel, G, Lopez, C, del Valle, J, Campos, O, Santacana, M, Matias-Guiu, X, Lazaro, C, Valle, L, Brunet, J, Pineda, M, Capella, G
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2020
País:España
Institución:Fundación para el Fomento de la Investigación Sanitaria y Biomédica de la Comunitat Valenciana (FISABIO)
Repositorio:r-FISABIO. Repositorio Institucional de Producción Científica
OAI Identifier:oai:fisabio.fundanetsuite.com:p12846
Acceso en línea:https://fisabio.portalinvestigacion.com/publicaciones/12846
Access Level:acceso abierto
Palabra clave:Lynch syndrome
Lynch-like syndrome
variant of unknown significance
epimutation
mismatch repair
methylation
cancer genes panel
next generation sequencing
Descripción
Sumario:The causal mechanism for cancer predisposition in Lynch-like syndrome (LLS) remains unknown. Our aim was to elucidate the constitutional basis of mismatch repair (MMR) deficiency in LLS patients throughout a comprehensive (epi)genetic analysis. One hundred and fifteen LLS patients harboring MMR-deficient tumors and no germline MMR mutations were included. Mutational analysis of 26 colorectal cancer (CRC)-associated genes was performed. Pathogenicity of MMR variants was assessed by splicing and multifactorial likelihood analyses. Genome-wide methylome analysis was performed by the Infinium Human Methylation 450K Bead Chip. The multigene panel analysis revealed the presence of two MMR gene truncating mutations not previously found. Of a total of 15 additional MMR variants identified, five -present in 6 unrelated individuals- were reclassified as pathogenic. In addition, 13 predicted deleterious variants in other CRC-predisposing genes were found in 12 probands. Methylome analysis detected one constitutionalMLH1epimutation, but no additional differentially methylated regions were identified in LLS compared to LS patients or cancer-free individuals. In conclusion, the use of an ad-hoc designed gene panel combined with pathogenicity assessment of variants allowed the identification of deleterious MMR mutations as well as new LLS candidate causal genes. Constitutional epimutations in non-LS-associated genes are not responsible for LLS.