Heritable somatic methylation and inactivation of MSH2 in families with Lynch syndrome due to deletion of the 3′ exons of TACSTD1

• Published in: Nature genetics Vol. 41; no. 1; pp. 112 - 117
• Main Authors: van Kessel, Ad Geurts, Hoenselaar, Eveline, Voorendt, Marsha, Kuiper, Roland P, Lee, Tracy Y H, Hendriks-Cornelissen, Sandra J B, Yuen, Siu Tsan, van Krieken, J Han J M, Leung, Suet Yi, Hoogerbrugge, Nicoline, Chan, Tsun Leung, Bodmer, Danielle, Ligtenberg, Marjolijn J L, Goossens, Monique, Hebeda, Konnie M, Tsui, Wai Yin, Brunner, Han G, Kong, Chi Kwan
• Format: Journal Article
• Language: English
• Published: New York Nature Publishing Group US 01-01-2009; Nature Publishing Group
• Subjects: Adolescent; Adult; Agriculture; Alleles; Animal Genetics and Genomics; Antigens, Neoplasm - genetics; Asian Continental Ancestry Group; Base Sequence; Biological and medical sciences; Biomedical and Life Sciences; Biomedicine; Cancer Research; Cell Adhesion Molecules - genetics; China; Colorectal cancer; Colorectal Neoplasms, Hereditary Nonpolyposis - genetics; DNA Methylation; Epithelial Cell Adhesion Molecule; European Continental Ancestry Group - genetics; Exons - genetics; Families & family life; Family; Female; Fundamental and applied biological sciences. Psychology; Gastroenterology. Liver. Pancreas. Abdomen; Gene Function; Gene mutations; Genes; Genetic aspects; Genetics of eukaryotes. Biological and molecular evolution; Health aspects; Human Genetics; Humans; Inactivation; Inheritance Patterns - genetics; letter; Male; Medical sciences; Methylation; Microsatellite Instability; Middle Aged; Minority & ethnic groups; Molecular Sequence Data; Mutation; MutS Homolog 2 Protein - genetics; Netherlands; Open Reading Frames - genetics; Pedigree; Promoter Regions, Genetic - genetics; Risk factors; Sequence Deletion - genetics; Stomach. Duodenum. Small intestine. Colon. Rectum. Anus; Tumors; Hereditary nonpolyposis colorectal cancer; Rectal disease; Malignant tumor; Inactivation; Genetic disease; Repair gene; Colonic disease; Exon; Deletion; Digestive diseases; Intestinal disease; Methylation; Cancer
• ISSN: 1061-4036; 1546-1718
• DOI: 10.1038/ng.283

Lynch syndrome patients are susceptible to colorectal and endometrial cancers owing to inactivating germline mutations in mismatch repair genes, including MSH2 (ref. 1). Here we describe patients from Dutch and Chinese families with MSH2-deficient tumors carrying heterozygous germline deletions of the last exons of TACSTD1, a gene directly upstream of MSH2 encoding Ep-CAM. Due to these deletions, transcription of TACSTD1 extends into MSH2. The MSH2 promoter in cis with the deletion is methylated in Ep-CAM positive but not in Ep-CAM negative normal tissues, thus revealing a correlation between activity of the mutated TACSTD1 allele and epigenetic inactivation of the corresponding MSH2 allele. Gene silencing by transcriptional read-through of a neighboring gene in either sense, as demonstrated here, or antisense direction, could represent a general mutational mechanism. Depending on the expression pattern of the neighboring gene that lacks its normal polyadenylation signal, this may cause either generalized or mosaic patterns of epigenetic inactivation.