| 1. |
- Eriksson, D, et al.
(författare)
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Extended exome sequencing identifies BACH2 as a novel major risk locus for Addison's disease
- 2016
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Ingår i: Journal of Internal Medicine. - : Wiley. - 0954-6820 .- 1365-2796. ; 286:6, s. 595-608
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Autoimmune disease is one of the leading causes of morbidity and mortality worldwide. In Addison's disease, the adrenal glands are targeted by destructive autoimmunity. Despite being the most common cause of primary adrenal failure, little is known about its aetiology.METHODS: To understand the genetic background of Addison's disease, we utilized the extensively characterized patients of the Swedish Addison Registry. We developed an extended exome capture array comprising a selected set of 1853 genes and their potential regulatory elements, for the purpose of sequencing 479 patients with Addison's disease and 1394 controls.RESULTS: We identified BACH2 (rs62408233-A, OR = 2.01 (1.71-2.37), P = 1.66 × 10(-15) , MAF 0.46/0.29 in cases/controls) as a novel gene associated with Addison's disease development. We also confirmed the previously known associations with the HLA complex.CONCLUSION: Whilst BACH2 has been previously reported to associate with organ-specific autoimmune diseases co-inherited with Addison's disease, we have identified BACH2 as a major risk locus in Addison's disease, independent of concomitant autoimmune diseases. Our results may enable future research towards preventive disease treatment.
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| 2. |
- Dahlqvist, Johanna, 1979-, et al.
(författare)
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Identification and functional characterization of a novel susceptibility locus for small vessel vasculitis with MPO-ANCA
- 2022
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Ingår i: Rheumatology. - Oxford, United Kingdom : Oxford University Press (OUP). - 1462-0324 .- 1462-0332. ; 61:8, s. 3461-3470
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Tidskriftsartikel (refereegranskat)abstract
- Objective To identify and characterize genetic loci associated with the risk of developing ANCA-associated vasculitides (AAV). Methods Genetic association analyses were performed after Illumina sequencing of 1853 genes and subsequent replication with genotyping of selected single nucleotide polymorphisms in a total cohort of 1110 Scandinavian cases with granulomatosis with polyangiitis or microscopic polyangiitis, and 1589 controls. A novel AAV-associated single nucleotide polymorphism was analysed for allele-specific effects on gene expression using luciferase reporter assay. Results PR3-ANCA(+) AAV was significantly associated with two independent loci in the HLA-DPB1/HLA-DPA1 region [rs1042335, P = 6.3 x 10(-61), odds ratio (OR) 0.10; rs9277341, P = 1.5 x 10(-44), OR 0.22] and with rs28929474 in the SERPINA1 gene (P = 2.7 x 10(-10), OR 2.9). MPO-ANCA(+) AAV was significantly associated with the HLA-DQB1/HLA-DQA2 locus (rs9274619, P = 5.4 x 10(-25), OR 3.7) and with a rare variant in the BACH2 gene (rs78275221, P = 7.9 x 10(-7), OR 3.0), the latter a novel susceptibility locus for MPO-ANCA(+) granulomatosis with polyangiitis/microscopic polyangiitis. The rs78275221-A risk allele reduced luciferase gene expression in endothelial cells, specifically, as compared with the non-risk allele. Conclusion We identified a novel susceptibility locus for MPO-ANCA(+) AAV and propose that the associated variant is of mechanistic importance, exerting a regulatory function on gene expression in specific cell types.
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| 3. |
- Eriksson, Daniel, et al.
(författare)
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Common genetic variation in the autoimmune regulator (AIRE) locus is associated with autoimmune Addison’s disease in Sweden
- 2018
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Ingår i: Scientific Reports. - : Nature Publishing Group. - 2045-2322. ; 8:1
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Tidskriftsartikel (refereegranskat)abstract
- Autoimmune Addison's disease (AAD) is the predominating cause of primary adrenal failure. Despite its high heritability, the rarity of disease has long made candidate-gene studies the only feasible methodology for genetic studies. Here we conducted a comprehensive reinvestigation of suggested AAD risk loci and more than 1800 candidate genes with associated regulatory elements in 479 patients with AAD and 2394 controls. Our analysis enabled us to replicate many risk variants, but several other previously suggested risk variants failed confirmation. By exploring the full set of 1800 candidate genes, we further identified common variation in the autoimmune regulator (AIRE) as a novel risk locus associated to sporadic AAD in our study. Our findings not only confirm that multiple loci are associated with disease risk, but also show to what extent the multiple risk loci jointly associate to AAD. In total, risk loci discovered to date only explain about 7% of variance in liability to AAD in our study population.
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| 4. |
- Mathioudaki, Argyri, Ph.D student, 1986-, et al.
(författare)
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Allele frequency spectrum of known ankylosing spondylitis associated variants in a Swedish population
- 2022
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Ingår i: Scandinavian Journal of Rheumatology. - : Informa UK Limited. - 0300-9742 .- 1502-7732. ; 51:1, s. 21-24
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Tidskriftsartikel (refereegranskat)abstract
- Objective: The genetic predisposition to ankylosing spondylitis (AS) has been most widely studied in cohorts with European ancestry. However, within Europe, disease prevalence is higher in Sweden. Given this, we aimed to characterize known AS susceptibility variants in a homogeneous Swedish data set, assessing reproducibility and direction of effect. Method: The power to detect association within an existing Swedish targeted sequencing study (381 controls; 310 AS cases) was examined, and a set of published associations (n = 151) was intersected with available genotypes. Association to disease was calculated using logistic regression accounting for population structure, and HLA-B27 status was determined with direct polymerase chain reaction genotyping. Results: The cases were found to be 92.3% HLA-B27 positive, with the data set showing >= 80% predictive power to replicate associations, with odds ratios >= 1.6 over a range of allele frequencies (0.1-0.7). Thirty-four markers, representing 23 gene loci, were available for investigation. The replicated variants tagged MICA and IL23R loci (p < 1.47 x 10(-3)), with variable direction of effect noted for gene loci IL1R1 and MST1. Conclusion: The Swedish data set successfully replicated both major histocompatibility complex (MHC) and non-MHC loci, and revealed a different replication pattern compared to discovery data sets. This was possibly due to population demographics, including HLA-B27 frequency and measured comorbidities.
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| 5. |
- Mathioudaki, Argyri, Ph.D student, 1986-, et al.
(författare)
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Replication and fine mapping of ankylosing spondylitis replicated loci in the Swedish population reveal different CCHCR1 protective haplotypes
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Background: The genetics of ankylosing spondylitis (AS) derives mainly from studies performed in large cohorts of British origin. However, within Europe, disease prevalence is higher in Sweden, and so we investigated the reproducibility of known AS susceptibility patterns in a homogeneous Swedish cohort.Methods: The replication power of the Swedish cohort was examined and a set of published SNP associations intersected with genotypes from an existing targeted sequencing study using these individuals (381 controls; 310 AS cases). To elucidate whether replication patterns derived from population subsampling or genetic similarity, allele frequency data from additional British and Swedish control populations were examined for genetic differentiation (FST). Replicated loci were fine mapped to investigate associations in more detail, and signals were dissected with haplotype analysis and functional annotation.Results: The study had 80% power to find variants of strong effect (Odds ratio, OR>2) given a wide range of risk allele frequencies (0.2-3), tagging HLA-B,CCHCR1and IL23R. The replication pattern was not due to European population genetic distance and fine mapping revealed genome-wide repositioned associations in HLA-Band CCHCR1, independent from the published associations (p-value < 2 x10-8, r2 < 0.3). The CCHCR1 locus showed two protective haplotype blocks (B1-1 and B2-1), independent from HLA-B signals (B1-1: r2 = 0.39, B2-2:r2=0.07), where 74% of controls were carrying 2 copies of the protective haplotypes (B1-1 and B2-1: OR=0.3, p-value = 1.2 x 10-45). Interestingly, while both haplotypes span CCHCR1, the effect of each haplotype is likely in cis, with eQTL evidence pointing to the regulation of TCF19(B1-1) and POU5F1(B1-2).Conclusions: Both European populations share key disease loci, but the Swedish cohort revealed fine-scale genetic differences, that may point to gene regulation. This study utilized a different variant resolution, and by doing so demonstrated that smaller populations have the potential to reveal new AS pathogenesis mechanisms and that further study of the Swedish population is warranted.
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| 6. |
- Mathioudaki, Argyri, Ph.D student, 1986-, et al.
(författare)
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Targeted sequencing reveals the somatic mutation landscape in a Swedish breast cancer cohort
- 2020
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 10:1
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Tidskriftsartikel (refereegranskat)abstract
- Breast cancer (BC) is a genetically heterogeneous disease with high prevalence in Northern Europe. However, there has been no detailed investigation into the Scandinavian somatic landscape. Here, in a homogeneous Swedish cohort, we describe the somatic events underlying BC, leveraging a targeted next-generation sequencing approach. We designed a 20.5 Mb array targeting coding and regulatory regions of genes with a known role in BC (n = 765). The selected genes were either from human BC studies (n = 294) or from within canine mammary tumor associated regions (n = 471). A set of predominantly estrogen receptor positive tumors (ER + 85%) and their normal tissue counterparts (n = 61) were sequenced to ~ 140 × and 85 × mean target coverage, respectively. MuTect2 and VarScan2 were employed to detect single nucleotide variants (SNVs) and copy number aberrations (CNAs), while MutSigCV (SNVs) and GISTIC (CNAs) algorithms estimated the significance of recurrent somatic events. The significantly mutated genes (q ≤ 0.01) were PIK3CA (28% of patients), TP53 (21%) and CDH1 (11%). However, histone modifying genes contained the largest number of variants (KMT2C and ARID1A, together 28%). Mutations in KMT2C were mutually exclusive with PI3KCA mutations (p ≤ 0. 001) and half of these affect the formation of a functional PHD domain. The tumor suppressor CDK10 was deleted in 80% of the cohort while the oncogene MDM4 was amplified. Mutational signature analyses pointed towards APOBEC deaminase activity (COSMIC signature 2) and DNA mismatch repair (COSMIC signature 6). We noticed two significantly distinct patterns related to patient age; TP53 being more mutated in the younger group (29% vs 9% of patients) and CDH23 mutations were absent from the older group. The increased somatic mutation prevalence in the histone modifying genes KMT2C and ARID1A distinguishes the Swedish cohort from previous studies. KMT2C regulates enhancer activation and assists tumor proliferation in a hormone-rich environment, possibly pointing to a role in ER + BC, especially in older cases. Finally, age of onset appears to affect the mutational landscape suggesting that a larger age-diverse population incorporating more molecular subtypes should be studied to elucidate the underlying mechanisms.
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| 7. |
- Mathioudaki, Argyri, Ph.D student, 1986-, et al.
(författare)
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The sex-stratified genetic architecture of ankylosing spondylitis
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Sexual dimorphism is an emerging feature of ankylosing spondylitis (AS), a chronic rheumatic condition affecting upto three times more men than women. Using 691 individuals from a Swedish case-control cohort, we revealed thatsex biases are also a hallmark of AS genetic predisposition, and that this multifactorial disease is in part driven byboth rare and common variants. We identified SNPs via the targeted re-sequencing of 7 270 coding and non-codingloci, and assessed novel patterns of association with both single marker and aggregate loci SKAT tests. The malespecific RUNX3 locus (including rs7414934, OR=2.58, p=1.7x10-5) and female specific MICB SKAT locus (27variants, p=1.2x10-6; rs3828903, OR=4.62, p=6.2x10-13) exceeded discovery thresholds. Multiple risk variants fromeach locus were shown to be functionally active in immune (Jurkat), skin (HaCat) and bone (SaOS-2) cell lines.Differential patterns of genetic predisposition may point to alternative disease mechanisms in male and femalepatients. Genetic and functional analyses demonstrated that risk alleles should not be considered in isolation and thatassociated variants would likely affect gene regulation across multiple tissues. This work illustrates the need toconsider the contribution of sex to the genetics of AS and the duality that individual loci may play in the key clinical outcomes of disease.
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| 8. |
- Nordin, Jessika, et al.
(författare)
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Association of Protective HLA-A With HLA-B∗27 Positive Ankylosing Spondylitis
- 2021
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Ingår i: Frontiers in Genetics. - Lausanne, Switzerland : Frontiers Media S.A.. - 1664-8021. ; 12
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: To further elucidate the role of the MHC in ankylosing spondylitis by typing 17 genes, searching for HLA-B∗27 independent associations and assessing the impact of sex on this male biased disease.Methods: High-confidence two-field resolution genotyping was performed on 310 cases and 2196 controls using an n-1 concordance method. Protein-coding variants were called from next-generation sequencing reads using up to four software programs and the consensus result recorded. Logistic regression tests were applied to the dataset as a whole, and also in stratified sets based on sex or HLA-B∗27 status. The amino acids driving association were also examined.Results: Twenty-five HLA protein-coding variants were significantly associated to disease in the population. Three novel protective associations were found in a HLA-B∗27 positive population, HLA-A∗24:02 (OR = 0.4, CI = 0.2–0.7), and HLA-A amino acids Leu95 and Gln156. We identified a key set of seven loci that were common to both sexes, and robust to change in sample size. Stratifying by sex uncovered three novel risk variants restricted to the female population (HLA-DQA1∗04.01, -DQB1∗04:02, -DRB1∗08:01; OR = 2.4–3.1). We also uncovered a set of neutral variants in the female population, which in turn conferred strong effects in the male set, highlighting how population composition can lead to the masking of true associations.Conclusion: Population stratification allowed for a nuanced investigation into the tightly linked MHC region, revealing novel HLA-B∗27 signals as well as replicating previous HLA-B∗27 dependent results. This dissection of signals may help to elucidate sex biased disease predisposition and clinical progression.
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| 9. |
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| 10. |
- Nordin, Jessika
(författare)
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Human leukocyte antigen in sickness and in health : Ankylosing spondylitis and HLA in Sweden
- 2019
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The human leukocyte antigen (HLA) plays a major role in keeping us healthy, but some of the HLA alleles can contribute to disease susceptibility. One example is HLA-B*27, which confers increased susceptibility of ankylosing spondylitis and represents one of the strongest genetic associations found in any common human disease. Ankylosing spondylitis shows a strong sex ratio skew (2-3:1 male to female) and studies confirm the existence of sexual-dimorphism in the presentation of this disease. The genetic predisposition for this, however, has not previously been studied. A Swedish ankylosing spondylitis population was sequenced with a targeted array to investigate the existence of sex-specific associations. RUNX3 was revealed to be associated in males by a univariate test, while aggregate tests revealed the HLA gene MICB to be associated in females. Functional validation demonstrated that the risk variants in RUNX3 increase expression, and MICB changed the transcription factor binding sites. Interestingly, since the disease involves bone changes, both RUNX3 and one of the MICB variants had effect in the bone cell line, SaOS-2.In order to help researchers obtain more controls for HLA analysis, an HLA allele bioresource (SweHLA) was generated from 1,000 Swedish genomes. The alleles were typed with three to four HLA typing software programs and results were combined by an n-1methodology. This produced high quality alleles where the bias from each software program was diminished.The methodology from SweHLA was utilised to study HLA in ankylosing spondylitis. To investigate both sex-specific predisposition and HLA-B*27 independence, samples were subdivided into two populations (one population with mixed HLA-B*27 positive and negative samples and one with only HLA-B*27 positive samples) that in turn were grouped by sex. In the mixed population, several alleles were replicated from previous studies. This study also revealed three female-specific alleles, two of which were new and one that had previously been associated to the severity of radiological changes. The HLA-B*27 population revealed a previously unknown protective allele, HLA-A*24:02. Through deeper examination of the HLA-B*27 population, two amino acids in HLA-A, position 119 in the whole set and position 180 in the male set, were revealed to be protective.This thesis brings new insight into the genetic predisposition for a sex-skewed disease, demonstrating how sexual-dimorphism can be reflected in the genetic predisposition, hopefully leading to more similar studies. It also highlights the importance of methodology and demonstrate the drastic biases that can be imparted by software programs.
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