| 1. |
- Bengtsson, Daniel, 1975-, et al.
(författare)
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Corticotroph Pituitary Carcinoma in a Patient With Lynch Syndrome (LS) and Pituitary Tumors in a Nationwide LS Cohort
- 2017
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Ingår i: Journal of Clinical Endocrinology and Metabolism. - : OXFORD UNIV PRESS INC. - 0021-972X .- 1945-7197. ; 102:11, s. 3928-3932
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Tidskriftsartikel (refereegranskat)abstract
- Context: Lynch syndrome (LS) is a cancer-predisposing syndrome caused by germline mutations in genes involved in DNA mismatch repair (MMR). Patients are at high risk for several types of cancer, but pituitary tumors have not previously been reported. Case: A 51-year-old man with LS (MSH2 mutation) and a history of colon carcinoma presented with severe Cushing disease and a locally aggressive pituitary tumor. The tumor harbored a mutation consistent with the patients germline mutation and displayed defect MMR function. Sixteen months later, the tumor had developed into a carcinoma with widespread liver metastases. The patient prompted us to perform a nationwide study in LS. Nationwide Study: A diagnosis consistent with a pituitary tumor was sought for in the Swedish National Patient Registry. In 910 patients with LS, representing all known cases in Sweden, another two clinically relevant pituitary tumors were found: an invasive nonsecreting macroadenoma and a microprolactinoma (i.e., in total three tumors vs. one expected). Conclusion: Germline mutations in MMR genes may contribute to the development and/or the clinical course of pituitary tumors. Because tumors with MMR mutations are susceptible to treatment with immune checkpoint inhibitors, we suggest to actively ask for a family history of LS in the workup of patients with aggressive pituitary tumors.
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| 2. |
- Karimi, Masoud, et al.
(författare)
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A retrospective study of extracolonic, non-endometrial cancer in Swedish Lynch syndrome families
- 2018
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Ingår i: Hereditary Cancer in Clinical Practice. - : BMC. - 1731-2302 .- 1897-4287. ; 16
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Tidskriftsartikel (refereegranskat)abstract
- BackgroundLynch Syndrome is an autosomal dominant cancer syndrome caused by pathogenic germ-line variants in one of the DNA-mismatch-repair (MMR) genes MLH1, MSH2, MSH6 or PMS2. Carriers are predisposed to colorectal and endometrial cancer, but also other cancer types. The purpose of this retrospective study was to characterize the tumour spectrum of the Swedish Lynch syndrome families.MethodsData were obtained from genetically verified 235 Lynch families from five of the six health care regions in Sweden. The material was stratified for gender, primary cancer, age and mutated gene and the relative proportions of specific cancer types were compared to those in the general population.ResultsA total of 1053 family members had 1493 cancer diagnoses of which 1011 were colorectal or endometrial cancer. Individuals with pathogenic variants in MLH1 and MSH2 comprised 78% of the cohort. Among the 482 non-colorectal/non-endometrial cancer diagnoses, MSH2 carriers demonstrated a significantly increased proportion of urinary tract, gastric, small bowel, ovarian and non-melanoma skin cancer compared to the normal population. MLH1 carriers had an elevated proportion of gastrointestinal cancers (gastric, small bowel, pancreas), while MSH6 carriers had more ovarian cancer than expected. Gastric cancer was predominantly noted in older generations.ConclusionLynch syndrome confers an increased risk for multiple cancers other than colorectal and endometrial cancer. The proportions of other cancers vary between different MMR genes, with highest frequency in MSH2-carriers. Gender and age also affect the tumour spectrum, demonstrating the importance of additional environmental and constitutional parameters in determining the predisposition for different cancer types.
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| 3. |
- Karimi, Masoud, et al.
(författare)
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A retrospective study of extracolonic, non-endometrial cancer in Swedish Lynch syndrome families 11 Medical and Health Sciences 1112 Oncology and Carcinogenesis 11 Medical and Health Sciences 1117 Public Health and Health Services
- 2018
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Ingår i: Hereditary Cancer in Clinical Practice. - : Springer Science and Business Media LLC. - 1731-2302 .- 1897-4287. ; 16:1
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Tidskriftsartikel (refereegranskat)abstract
- Background: Lynch Syndrome is an autosomal dominant cancer syndrome caused by pathogenic germ-line variants in one of the DNA-mismatch-repair (MMR) genes MLH1, MSH2, MSH6 or PMS2. Carriers are predisposed to colorectal and endometrial cancer, but also other cancer types. The purpose of this retrospective study was to characterize the tumour spectrum of the Swedish Lynch syndrome families. Methods: Data were obtained from genetically verified 235 Lynch families from five of the six health care regions in Sweden. The material was stratified for gender, primary cancer, age and mutated gene and the relative proportions of specific cancer types were compared to those in the general population. Results: A total of 1053 family members had 1493 cancer diagnoses of which 1011 were colorectal or endometrial cancer. Individuals with pathogenic variants in MLH1 and MSH2 comprised 78% of the cohort. Among the 482 non-colorectal/non-endometrial cancer diagnoses, MSH2 carriers demonstrated a significantly increased proportion of urinary tract, gastric, small bowel, ovarian and non-melanoma skin cancer compared to the normal population. MLH1 carriers had an elevated proportion of gastrointestinal cancers (gastric, small bowel, pancreas), while MSH6 carriers had more ovarian cancer than expected. Gastric cancer was predominantly noted in older generations. Conclusion: Lynch syndrome confers an increased risk for multiple cancers other than colorectal and endometrial cancer. The proportions of other cancers vary between different MMR genes, with highest frequency in MSH2-carriers. Gender and age also affect the tumour spectrum, demonstrating the importance of additional environmental and constitutional parameters in determining the predisposition for different cancer types.
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| 4. |
- Klarskov, Louise, et al.
(författare)
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Interobserver variability in the evaluation of mismatch repair protein immunostaining
- 2010
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Ingår i: Human Pathology. - : Elsevier BV. - 1532-8392 .- 0046-8177. ; 41:10, s. 1387-1396
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Tidskriftsartikel (refereegranskat)abstract
- Immunohistochemical staining for mismatch repair proteins has during recent years been established as a routine analysis in many pathology laboratories with the aim to identify tumors linked to the hereditary nonpolyposis colorectal cancer syndrome. Despite widespread application, data on reliability are lacking. We therefore evaluated interobserver variability among 6 pathologists, 3 experienced gastrointestinal pathologists and 3 residents. In total, 225 immunohistochemically stained colorectal cancers were evaluated as having normal, weak, loss of, or nonevaluable mismatch repair protein staining. Full consensus was achieved in 51% of the stainings for MLH1, 61% for PMS2, 83% for MSH2, and 45% for MSH6. Weak stainings were the main cause of reduced consensus, whereas contradictory evaluations with normal as well as loss of staining were reported in 2% to 6% of the tumors. Interobserver variability was considerable, though experienced pathologists and residents reached the same level of consensus. Because results from immunohistochemical mismatch repair protein stainings are used for decisions on mutation analysis and as an aid in the interpretation of gene variants of unknown significance in hereditary nonpolyposis colorectal cancer, the interobserver variability identified highlights the need for quality assessment programs, including guidelines for classification of different expression patterns. (C) 2010 Elsevier Inc. All rights reserved.
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| 5. |
- Näslund, Kalle, et al.
(författare)
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Genome-wide prediction of human VNTRs
- 2005
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Ingår i: Genomics. - : Elsevier BV. - 0888-7543 .- 1089-8646. ; 85:1, s. 24-35
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Tidskriftsartikel (refereegranskat)abstract
- Polymorphic minisatellites, also known as variable number of tandem repeats (VNTRs), are tandem repeat regions that show variation in the number of repeat units among chromosomes in a population. Currently, there are no general methods for predicting which minisatellites have a high probability of being polymorphic, given their sequence characteristics. An earlier approach has focused on potentially highly polymorphic and hypervariable minisatellites, which make up only a small fraction of all minisatellites in the human genome. We have developed a model, based on available minisatellite and VNTR sequence data, that predicts the probability that a minisatellite (unit size > or = 6 bp) identified by the computer program Tandem Repeats Finder is polymorphic (VNTR). According to the model, minisatellites with high copy number and high degree of sequence similarity are most likely to be VNTRs. This approach was used to scan the draft sequence of the human genome for VNTRs. A total of 157,549 minisatellite repeats were found, of which 29,224 are predicted to be VNTRs. Contrary to previous results, VNTRs appear to be widespread and abundant throughout the human genome, with an estimated density of 9.1 VNTRs/Mb.
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| 6. |
- Nääs, Charlotta, et al.
(författare)
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Patients’ perceptions and practices of informing relatives : a qualitative study within a randomised trial on healthcare-assisted risk disclosure
- 2024
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Ingår i: European Journal of Human Genetics. - : Springer Nature. - 1018-4813 .- 1476-5438.
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Tidskriftsartikel (refereegranskat)abstract
- In a multicentre randomised controlled trial (DIRECT), we evaluate whether an intervention of providing direct letters from healthcare professionals to at-risk relatives (ARRs) affects the proportion of ARRs contacting a cancer genetics clinic, compared with patient-mediated disclosure alone (control). With the aim to explore how the patients included in the trial perceived and performed risk communication with their ARRs we analysed 17 semi-structured interviews with reflexive thematic analysis. All patients described that they disclosed risk information to all close relatives themselves. No integrity-related issues were reported by patients offered the intervention, and all of them accepted direct letters to all their ARRs. Patients’ approaches to informing distant relatives were unpredictable and varied from contacting all distant ARRs, sharing the burden with the family, utilising the offer of sending direct letters, vaguely relying on others to inform, or postponing disclosure. Most patients limited their responsibility to the disclosure, although others wanted relatives to get genetic counselling or felt a need to provide additional information to the ARRs before ending their mission. We also identified confusion about the implication of test results, who needed risk information, and who was responsible for informing ARRs. These misunderstandings possibly also affected risk disclosure. This study revealed that despite accepting the direct letters to be sent to all relatives, the patients also contributed to risk disclosure in other ways. It was only in some situations to distant relatives that the healthcare-assisted letter was the only means of communication to the ARRs.
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| 7. |
- Salomé, Jenny von
(författare)
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Clinical aspects of Lynch syndrome
- 2020
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Colorectal cancer is the second most common cancer in women and the third most common cancer in men worldwide, with 1.8 million new cases and almost 861000 deaths in 2018. Approximately 5–10% of the annual CRC burden can be attributed to inherited high risk germline mutations. The most common inherited colon cancer syndrome is Lynch syndrome, which accounts for up to 5% of all CRCs. Lynch syndrome displays both genotypic and phenotypic heterogeneity and can be suspected on the basis of a strong family history of colorectal- or endometrial cancer, but also of other tumors. Genetic counselling is recommended for families with Lynch syndrome, to provide the patient and family members with information about cancers risk and options for surveillance and management. In paper I we compared disease associated haplotypes in families from Sweden, Germany and France, all carrying the MLH1 mutation c.2059C>T, in order to elucidate if this is a founder mutation. When analyzing the haplotype in the families with Swedish descent, a shared region of approximately 0.9–2.8 Mb was identified. The MLH1 c.2059C>T mutation thus act as a founder in the Swedish population, but is also found in Europe, Asia and Australia, indicating that this is a recurring mutation globally albeit with a very low allele frequency. In paper II and III we investigated if genetic anticipation was part of the clinical picture in a Swedish cohort of Lynch syndrome families, as well as in a larger European cohort of PMS2 mutation carriers. In paper II, a total 1003 proven mutation carriers from 239 families with Lynch syndrome were included. An anticipation effect of 2,55 years and hazard rate of 1.33 between generations was seen in families with MSH2 mutation. In addition, an anticipation effect of 7.33 years and a hazard ration of 1.86 per generation was shown in families with PMS2 mutation. In paper III, 637 individuals from 123 families with PMS2 mutation were recruited from Netherlands, Norway, Germany, Denmark, Spain, including the Swedish PMS2 patients in paper II. Participants were assigned mutation probabilities in cases of unknown carrier status. As opposed to the result in paper II, an anticipation effect initially shown in a crude analysis was no longer statistically significant when corrections were made for gender and birth cohort. In paper IV we characterized the tumor spectrum, excluding colorectal- and endometrial cancers, in a nationwide cohort of 235 Swedish Lynch syndrome families. Data was stratified for gender, primary cancer, age, and mutated gene. Relative proportions of specific cancer types were compared to corresponding proportions in the reference population from the national Swedish Cancer Registry. Individuals of both sexes in our cohort had a higher proportion of gastric cancer, small bowel cancer and urinary tract cancer compared to the general population. In female mutation carriers, the proportion of ovarian cancer and non-melanoma skin cancer was increased compared to the general population.
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| 8. |
- von Salomé, Jenny, et al.
(författare)
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Full-length sequence analysis of the HLA-DRB1 locus suggests a recent origin of alleles
- 2007
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Ingår i: Immunogenetics. - : Springer Science and Business Media LLC. - 0093-7711 .- 1432-1211. ; 59:4, s. 261-271
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Tidskriftsartikel (refereegranskat)abstract
- The HLA region harbors some of the most polymorphic loci in the human genome. Among them is the class II locus HLA-DRB1, with more than 400 known alleles. The age of the polymorphism and the rate at which new alleles are generated at HLA loci has caused much controversy over the years. Previous studies have mostly been restricted to the 270 base pairs that constitute the second exon and represent the most variable part of the gene. Here, we investigate the evolutionary history of the HLA-DRB1 locus on the basis of an analysis of 15 genomic full-length alleles (10–15 kb). In addition, the variation in 49 complete coding sequences and 322 exon 2 sequences were analyzed. When excluding exon 2 from the analysis, the diversity at the synonymous sites was found to be similar to the intron diversity. The overall diversity in noncoding region was also similar to the genome average. The DRB1*03 lineage has been found in human, chimpanzee, bonobo, gorilla, and orangutan. An ancestral “proto HLA-DRB1*03 lineage” appeared to have diverged in the last 5 million years into the human-specific lineages *08, *11, *13, and *14. With exception to exon 2, both the coding- and the noncoding diversity suggests a recent origin (<1 million years ago) for most of the alleles at the HLA-DRB1 locus. Sites encoding for amino acids involved in antigen binding [antigen recognizing sites (ARS)] appear to have a more ancient origin. Taken together, the recent origin of most alleles, the high diversity between allelic lineages, and the ancient origin of sequence motifs in exon 2, is consistent with a relatively rapid generation of novel alleles by gene conversion like events.
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| 9. |
- von Salomé, Jenny, et al.
(författare)
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Genetic anticipation in Swedish Lynch syndrome families
- 2017
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Ingår i: PLoS Genetics. - : Public Library of Science (PLoS). - 1553-7390 .- 1553-7404. ; 13:10
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Tidskriftsartikel (refereegranskat)abstract
- Among hereditary colorectal cancer predisposing syndromes, Lynch syndrome (LS) caused by mutations in DNA mismatch repair genes MLH1, MSH2, MSH6 or PMS2 is the most common. Patients with LS have an increased risk of early onset colon and endometrial cancer, but also other tumors that generally have an earlier onset compared to the general population. However, age at first primary cancer varies within families and genetic anticipation, i.e. decreasing age at onset in successive generations, has been suggested in LS. Anticipation is a well-known phenomenon in e.g neurodegenerative diseases and several reports have studied anticipation in heritable cancer. The purpose of this study is to determine whether anticipation can be shown in a large cohort of Swedish LS families referred to the regional departments of clinical genetics in Lund, Stockholm, Linköping, Uppsala and Umeå between the years 1990–2013. We analyzed a homogenous group of mutation carriers, utilizing information from both affected and non-affected family members. In total, 239 families with a mismatch repair gene mutation (96 MLH1 families, 90 MSH2 families including one family with an EPCAM–MSH2 deletion, 39 MSH6 families, 12 PMS2 families, and 2 MLH1+PMS2 families) comprising 1028 at-risk carriers were identified among the Swedish LS families, of which 1003 mutation carriers had available follow-up information and could be included in the study. Using a normal random effects model (NREM) we estimate a 2.1 year decrease in age of diagnosis per generation. An alternative analysis using a mixed-effects Cox proportional hazards model (COX-R) estimates a hazard ratio of exp(0.171), or about 1.19, for age of diagnosis between consecutive generations. LS-associated gene-specific anticipation effects are evident for MSH2 (2.6 years/generation for NREM and hazard ratio of 1.33 for COX-R) and PMS2 (7.3 years/generation and hazard ratio of 1.86). The estimated anticipation effects for MLH1 and MSH6 are smaller.
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| 10. |
- von Salomé, Jenny, et al.
(författare)
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Sequence features of HLA-DRB1 locus define putative basis for gene conversion and point mutations
- 2008
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Ingår i: BMC Genomics. - : Springer Science and Business Media LLC. - 1471-2164. ; 9, s. 228-
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: HLA/MHC class II molecules show high degree of polymorphism in the human population. The individual polymorphic motifs have been suggested to be propagated and mixed by transfer of genetic material (recombination, gene conversion) between alleles, but no clear molecular basis for this has been identified as yet. A large number of MHC class II allele sequences is publicly available and could be used to analyze the sequence features behind the recombination, revealing possible basis for such recombination processes both in HLA class II genes and other genes, which recombination acts upon. RESULTS: In this study we analyzed the vast dataset of human allelic variants (49 full coding sequences, 374 full exon 2 sequences) of the most polymorphic MHC class II locus, HLA-DRB1, and identified many previously unknown sequence features possibly contributing to the recombination. The CpG-dinucleotide content of exon 2 (containing the antigen-binding sites and subsequently a high degree of polymorphism) was much elevated as compared to the other exons despite similar overall G+C content. Furthermore, the CpG pattern was highly conserved. We also identified more complex, highly conserved sequence motifs in exon 2. Some of these can be identified as putative recombination motifs previously found in other genes, but most are previously unidentified. CONCLUSION: The identified sequence features could putatively act in recombination allowing either less (CpG dinucleotides) or more specific DNA cleavage (complex sequences) or homologous recombination (complex sequences).
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