| 1. |
- Rohlin, Anna, et al.
(författare)
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A mutation in POLE predisposing to a multi-tumour phenotype
- 2014
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Ingår i: International Journal of Oncology. - : Spandidos Publications. - 1019-6439 .- 1791-2423. ; 45:1, s. 77-81
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Tidskriftsartikel (refereegranskat)abstract
- Somatic mutations in the POLE gene encoding the catalytic subunit of DNA polymerase epsilon have been found in sporadic colorectal cancers (CRCs) and are most likely of importance in tumour development and/or progression. Recently, families with dominantly inherited colorectal adenomas and colorectal cancer were shown to have a causative heterozygous germline mutation in the proofreading exonuclease domain of POLE. The highly penetrant mutation was associated with predisposition to CRC only and no extra-colonic tumours were observed. We have identified a mutation in a large family in which the carriers not only developed CRC, they also demonstrate a highly penetrant predisposition to extra-intestinal tumours such as ovarian, endometrial and brain tumours. The mutation, NM_006231.2:c.1089C>A, p.Asn363Lys, also located in the proofreading exonuclease domain is directly involved in DNA binding. Theoretical prediction of the amino acid substitution suggests a profound effect of the substrate binding capability and a more severe impairment of the catalytic activity compared to the previously reported germline mutation. A possible genotype to phenotype correlation for deleterious mutations in POLE might exist that needs to be considered in the follow-up of mutation carriers.
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| 2. |
- Rohlin, Anna, et al.
(författare)
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GREM1 and POLE variants in hereditary colorectal cancer syndromes
- 2016
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Ingår i: Genes, Chromosomes and Cancer. - : Wiley. - 1045-2257 .- 1098-2264. ; 55:1
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Tidskriftsartikel (refereegranskat)abstract
- Hereditary factors are thought to play a role in at least one third of patients with colorectal cancer (CRC) but only a limited proportion of these have mutations in known high-penetrant genes. In a relatively large part of patients with a few or multiple colorectal polyps the underlying genetic cause of the disease is still unknown. Using exome sequencing in combination with linkage analyses together with detection of copy-number variations (CNV), we have identified a duplication in the regulatory region of the GREM1 gene in a family with an attenuated/atypical polyposis syndrome. In addition, 107 patients with colorectal cancer and/or polyposis were analyzed for mutations in the candidate genes identified. We also performed screening of the exonuclease domain of the POLE gene in a subset of these patients. The duplication of 16 kb in the regulatory region of GREM1 was found to be disease-causing in the family. Functional analyses revealed a higher expression of the GREM1 gene in colorectal tissue in duplication carriers. Screening of the exonuclease domain of POLE in additional CRC patients identified a probable causative novel variant c.1274A>G, p.Lys425Arg. In conclusion a high penetrant duplication in the regulatory region of GREM1, predisposing to CRC, was identified in a family with attenuated/atypical polyposis. A POLE variant was identified in a patient with early onset CRC and a microsatellite stable (MSS) tumor. Mutations leading to increased expression of genes can constitute disease-causing mutations in hereditary CRC syndromes. © 2015 The Authors. Genes, Chromosomes & Cancer Published by Wiley Periodicals, Inc.
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| 3. |
- Svensson, Sara, et al.
(författare)
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Merged testing for colorectal cancer syndromes and re-evaluation of genetic variants improve diagnostic yield: Results from a nationwide prospective cohort
- 2022
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Ingår i: Genes Chromosomes & Cancer. - : Wiley. - 1045-2257 .- 1098-2264. ; 61:10, s. 585-591
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Tidskriftsartikel (refereegranskat)abstract
- Approximately 5% of patients with colorectal cancer (CRC) have a Mendelian predisposition for the disease. Identification of the disease-causing genetic variant enables carrier testing and tailored cancer prevention within affected families. To determine the panorama and genetic variation of Mendelian CRC syndromes among referrals at the cancer genetics clinics in Sweden, 850 patients clinically selected for CRC genetic investigation were included in a prospective study that tested for all major hereditary polyposis and nonpolyposis CRC conditions. Genetically defined syndromes were diagnosed in 11% of the patients. Lynch syndrome was predominant (n = 73) followed by familial adenomatous polyposis (n = 12) and MUTYH-associated polyposis (n = 8); the latter of which two patients presented with CRC before polyposis was evident. One patient with a history of adolescent-onset CRC and polyposis had biallelic disease-causing variants diagnostic for constitutional mismatch repair deficiency syndrome. Post-study review of detected variants of unknown clinical significance (n = 129) resulted in the reclassification of variants as likely benign (n = 59) or as diagnostic for Lynch syndrome (n = 2). Our results reveal the panorama of Mendelian CRC syndromes at the cancer genetics clinics in Sweden and show that unified testing for polyposis and nonpolyposis CRC conditions as well as regular reexamination of sequence data improve the diagnostic yield.
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