Individuals with Lynch syndrome (LS), have an increased risk of developing cancer. Common genetic variants of telomerase reverse transcriptase (TERT) have been associated with a wide range of... Show moreIndividuals with Lynch syndrome (LS), have an increased risk of developing cancer. Common genetic variants of telomerase reverse transcriptase (TERT) have been associated with a wide range of cancers, including colorectal cancer (CRC) in LS. We combined genotype data from 1881 LS patients, carrying pathogenic variants in MLH1, MSH2 or MSH6, for rs2075786 (G>A, intronic variant), 1207 LS patients for rs2736108 (C>T, upstream variant) and 1201 LS patients for rs7705526 (C>A, intronic variant). The risk of cancer was estimated by heterozygous/homozygous odds ratio (OR) with mixed-effects logistic regression to adjust for gene/gender/country of sample origin considering family identity. The AA genotype of SNP rs2075786 is associated with 85% higher odds at developing cancer compared to GG genotype in MSH2 pathogenic variant carriers (p=0.0160). Kaplan-Meier analysis also shows an association for rs2075786; the AA allele for MSH2 variant carriers confers risk for earlier diagnosis of LS cancer (log-rank p=0.0011). We report a polymorphism in TERT to be a possible modifier of disease risk in MSH2 pathogenic variant carriers. The rs2075786 SNP in TERT is associated with a differential risk of developing cancer for MSH2 pathogenic variant carriers. Use of this information has the potential to personalise screening protocols for LS patients. Show less
Jansen, A.M.L.; Tops, C.M.J.; Ruano, D.; Eijk, R. van; Wijnen, J.T.; Broeke, S. ten; ... ; Morreau, H. 2020
Germline variants in the DNA mismatch repair (MMR) gene PMS2 cause 1-14% of all Lynch Syndrome cancers. Correct variant analysis of PMS2 is complex due to the presence of multiple pseudogenes and... Show moreGermline variants in the DNA mismatch repair (MMR) gene PMS2 cause 1-14% of all Lynch Syndrome cancers. Correct variant analysis of PMS2 is complex due to the presence of multiple pseudogenes and the occurrence of gene conversion. The analysis complexity increases in highly fragmented DNA from formalin-fixed paraffin-embedded (FFPE) tissue. Here we describe a reliable approach to detect true PMS2 variants in fragmented DNA. A custom NGS panel designed for FFPE tissue was used targeting four MMR genes, POLE and POLD1. Amplicon design for PMS2 was based on the position of paralogous sequence variants (PSVs) that distinguish PMS2 from its pseudogenes. PMS2 variants in exons 1-11 can be correctly curated based on this information. For exons 12-15 this is less reliable as these undergo gene conversion. Using this method, we screened PMS2 variants in 125 MMR-deficient tumors. Of the 125 tumors tested, six were unexplained MMR-deficient tumors with solitary PMS2 protein expression loss. In these six tumors two unclassified variants (class 3) and five variants likely affecting function (class 4/5) were detected in PMS2. One microsatellite unstable tumor with positive staining for all MMR proteins was found to carry a frameshift PMS2 variant (class 5). No class 4 or class 5 PMS2 variants were detected in tumors with other patterns of MMR protein expression loss. Show less
To establish whether existing mutation prediction models can identify which male breast cancer (MBC) patients should be offered BRCA1 and BRCA2 diagnostic DNA screening, we compared the performance... Show moreTo establish whether existing mutation prediction models can identify which male breast cancer (MBC) patients should be offered BRCA1 and BRCA2 diagnostic DNA screening, we compared the performance of BOADICEA, BRCAPRO and the Myriad prevalence table ('Myriad'). These models were evaluated using the family data of 307 Dutch MBC probands tested for BRCA1/2, 58 (19%) of whom were carriers. We compared the numbers of observed versus predicted carriers and assessed the area under the receiver operating characteristic (ROC) curve (AUC) for each model. BOADICEA predicted the total number of BRCA1/2 mutation carriers quite accurately (observed/predicted ratio: 0.94). When a cut-off of 10% and 20% prior probability was used, BRCAPRO showed a non-significant better performance (observed/predicted ratio BOADICEA: 0.81, 95% Confidence Interval (CI): (0.60-1.09) and 0.79, 95% CI: (0.57-1.09), vs. BRCAPRO: 1.02, 95% CI: (0.75-1.38) and 0.94, 95% CI: (0.68-1.31), respectively). Myriad underestimated the number of carriers in up to 69% of the cases. BRCAPRO showed a non-significant, higher AUC than BOADICEA (0.798 vs 0.776). Myriad showed a significantly lower AUC (0.671). BRCAPRO and BOADICEA can efficiently identify MBC patients as BRCA1/2 mutation carriers. Besides their general applicability, these tools will be of particular value in countries with limited healthcare resources. Show less
Jansen, A.M.L.; Crobach, S.; Geurts-Giele, W.R.R.; Akker, B.E.W.M. van den; Garcia, M.V.; Ruano, D.; ... ; Morreau, H. 2017
Familial adenomatous polyposis (FAP) is a dominantly inherited syndrome caused by germline mutations in the APC gene and characterized by the development of multiple colorectal adenomas and a high... Show moreFamilial adenomatous polyposis (FAP) is a dominantly inherited syndrome caused by germline mutations in the APC gene and characterized by the development of multiple colorectal adenomas and a high risk of developing colorectal cancer (CRC). The severity of polyposis is correlated with the site of the APC mutation. However, there is also phenotypic variability within families with the same underlying APC mutation, suggesting that additional factors influence the severity of polyposis. Genome-wide association studies identified several single nucleotide polymorphisms (SNPs) that are associated with CRC. We assessed whether these SNPs are associated with polyp multiplicity in proven APC mutation carriers. Sixteen CRC-associated SNPs were analysed in a cohort of 419 APC germline mutation carriers from 182 families. Clinical data were retrieved from the Dutch Polyposis Registry. Allele frequencies of the SNPs were compared for patients with < 100 colorectal adenomas versus patients with aeyen100 adenomas, using generalized estimating equations with the APC genotype as a covariate. We found a trend of association of two of the tested SNPs with the aeyen100 adenoma phenotype: the C alleles of rs16892766 at 8q23.3 (OR 1.71, 95 % CI 1.05-2.76, p = 0.03, dominant model) and rs3802842 at 11q23.1 (OR 1.51, 95 % CI 1.03-2.22, p = 0.04, dominant model). We identified two risk variants that are associated with a more severe phenotype in APC mutation carriers. These risk variants may partly explain the phenotypic variability in families with the same APC gene defect. Further studies with a larger sample size are recommended to evaluate and confirm the phenotypic effect of these SNPs in FAP. Show less
Jansen, A.M.L.; Wezel, T. van; Akker, B.E.W.M. van den; Garcia, M.V.; Ruano, D.; Tops, C.M.J.; ... ; Morreau, H. 2016
The Dutch Hereditary Cancer Registry was established in 1985 with the support of the Ministry of Health (VWS). The aims of the registry are: (1) to promote the identification of families with... Show moreThe Dutch Hereditary Cancer Registry was established in 1985 with the support of the Ministry of Health (VWS). The aims of the registry are: (1) to promote the identification of families with hereditary cancer, (2) to encourage the participation in surveillance programs of individuals at high risk, (3) to ensure the continuity of lifelong surveillance examinations, and (4) to promote research, in particular the improvement of surveillance protocols. During its early days the registry provided assistance with family investigations and the collection of medical data, and recommended surveillance when a family fulfilled specific diagnostic criteria. Since 2000 the registry has focused on family follow-up, and ensuring the quality of surveillance programs and appropriate clinical management. Since its founding, the registry has identified over 10,000 high-risk individuals with a diverse array of hereditary cancer syndromes. All were encouraged to participate in prevention programmes. The registry has published a number of studies that evaluated the outcome of surveillance protocols for colorectal cancer (CRC) in Lynch syndrome, as well as in familial colorectal cancer. In 2006, evaluation of the effect of registration and colonoscopic surveillance on the mortality rate associated with colorectal cancer (CRC) showed that the policy led to a substantial decrease in the mortality rate associated with CRC. Following discovery of MMR gene defects, the first predictive model that could select families for genetic testing was published by the Leiden group. In addition, over the years the registry has produced many cancer risk studies that have helped to develop appropriate surveillance protocols. Hereditary cancer registries in general, and the Lynch syndrome registry in particular, play an important role in improving the clinical management of affected families. Show less
Jansen, A.M.L.; Geilenkirchen, M.A.; Wezel, T. van; Jagmohan-Changur, S.C.; Ruano, D.; Klift, H.M. van der; ... ; Wijnen, J.T. 2016
This is the first study in sLS patients to include the entire genomic sequence of CRC susceptibility genes. An underlying somatic or germline MMR gene defect was identified in ten of 34 sLS... Show moreThis is the first study in sLS patients to include the entire genomic sequence of CRC susceptibility genes. An underlying somatic or germline MMR gene defect was identified in ten of 34 sLS patients (29%). In the remaining sLS patients, the underlying genetic defect explaining the MMR deficiency in their tumors might be found outside the genomic regions harboring the MMR and other known CRC susceptibility genes. Show less
Suerink, M.; Klift, H.M. van der; Broeke, S.W. ten; Dekkers, O.M.; Bernstein, I.; Munar, G.C.; ... ; Nielsen, M. 2016
