| 1. |
- Carlsson Almlöf, Jonas, et al.
(författare)
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Novel risk genes for systemic lupus erythematosus predicted by random forest classification
- 2017
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 7:1
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Tidskriftsartikel (refereegranskat)abstract
- Genome-wide association studies have identified risk loci for SLE, but a large proportion of the genetic contribution to SLE still remains unexplained. To detect novel risk genes, and to predict an individual's SLE risk we designed a random forest classifier using SNP genotype data generated on the "Immunochip" from 1,160 patients with SLE and 2,711 controls. Using gene importance scores defined by the random forest classifier, we identified 15 potential novel risk genes for SLE. Of them 12 are associated with other autoimmune diseases than SLE, whereas three genes (ZNF804A, CDK1, and MANF) have not previously been associated with autoimmunity. Random forest classification also allowed prediction of patients at risk for lupus nephritis with an area under the curve of 0.94. By allele-specific gene expression analysis we detected cis-regulatory SNPs that affect the expression levels of six of the top 40 genes designed by the random forest analysis, indicating a regulatory role for the identified risk variants. The 40 top genes from the prediction were overrepresented for differential expression in B and T cells according to RNA-sequencing of samples from five healthy donors, with more frequent over-expression in B cells compared to T cells.
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| 2. |
- Leonard, Dag, 1975-, et al.
(författare)
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Novel gene variants associated with cardiovascular disease in systemic lupus erythematosus and rheumatoid arthritis.
- 2018
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Ingår i: Annals of the Rheumatic Diseases. - : BMJ. - 0003-4967 .- 1468-2060. ; 77:7, s. 1063-1069
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVES: Patients with systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA) have increased risk of cardiovascular disease (CVD). We investigated whether single nucleotide polymorphisms (SNPs) at autoimmunity risk loci were associated with CVD in SLE and RA.METHODS: Patients with SLE (n=1045) were genotyped using the 200K Immunochip SNP array (Illumina). The allele frequency was compared between patients with and without different manifestations of CVD. Results were replicated in a second SLE cohort (n=1043) and in an RA cohort (n=824). We analysed publicly available genetic data from general population, performed electrophoretic mobility shift assays and measured cytokine levels and occurrence of antiphospholipid antibodies (aPLs).RESULTS: We identified two new putative risk loci associated with increased risk for CVD in two SLE populations, which remained after adjustment for traditional CVD risk factors. An IL19 risk allele, rs17581834(T) was associated with stroke/myocardial infarction (MI) in SLE (OR 2.3 (1.5 to 3.4), P=8.5×10-5) and RA (OR 2.8 (1.4 to 5.6), P=3.8×10-3), meta-analysis (OR 2.5 (2.0 to 2.9), P=3.5×10-7), but not in population controls. The IL19 risk allele affected protein binding, and SLE patients with the risk allele had increased levels of plasma-IL10 (P=0.004) and aPL (P=0.01). An SRP54-AS1 risk allele, rs799454(G) was associated with stroke/transient ischaemic attack in SLE (OR 1.7 (1.3 to 2.2), P=2.5×10-5) but not in RA. The SRP54-AS1 risk allele is an expression quantitative trait locus for four genes.CONCLUSIONS: The IL19 risk allele was associated with stroke/MI in SLE and RA, but not in the general population, indicating that shared immune pathways may be involved in the CVD pathogenesis in inflammatory rheumatic diseases.
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| 3. |
- Sandling, Johanna K., et al.
(författare)
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Molecular pathways in patients with systemic lupus erythematosus revealed by gene-centred DNA sequencing
- 2021
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Ingår i: Annals of the Rheumatic Diseases. - : BMJ. - 0003-4967 .- 1468-2060. ; 80:1, s. 109-117
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: Systemic lupus erythematosus (SLE) is an autoimmune disease with extensive heterogeneity in disease presentation between patients, which is likely due to an underlying molecular diversity. Here, we aimed at elucidating the genetic aetiology of SLE from the immunity pathway level to the single variant level, and stratify patients with SLE into distinguishable molecular subgroups, which could inform treatment choices in SLE. Methods: We undertook a pathway-centred approach, using sequencing of immunological pathway genes. Altogether 1832 candidate genes were analysed in 958 Swedish patients with SLE and 1026 healthy individuals. Aggregate and single variant association testing was performed, and we generated pathway polygenic risk scores (PRS). Results: We identified two main independent pathways involved in SLE susceptibility: T lymphocyte differentiation and innate immunity, characterised by HLA and interferon, respectively. Pathway PRS defined pathways in individual patients, who on average were positive for seven pathways. We found that SLE organ damage was more pronounced in patients positive for the T or B cell receptor signalling pathways. Further, pathway PRS-based clustering allowed stratification of patients into four groups with different risk score profiles. Studying sets of genes with priors for involvement in SLE, we observed an aggregate common variant contribution to SLE at genes previously reported for monogenic SLE as well as at interferonopathy genes. Conclusions: Our results show that pathway risk scores have the potential to stratify patients with SLE beyond clinical manifestations into molecular subsets, which may have implications for clinical follow-up and therapy selection.
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| 4. |
- Almlöf, Jonas Carlsson, et al.
(författare)
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Whole-genome sequencing identifies complex contributions to genetic risk by variants in genes causing monogenic systemic lupus erythematosus
- 2019
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Ingår i: Human Genetics. - : SPRINGER. - 0340-6717 .- 1432-1203. ; 138:2, s. 141-150
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Tidskriftsartikel (refereegranskat)abstract
- Systemic lupus erythematosus (SLE, OMIM 152700) is a systemic autoimmune disease with a complex etiology. The mode of inheritance of the genetic risk beyond familial SLE cases is currently unknown. Additionally, the contribution of heterozygous variants in genes known to cause monogenic SLE is not fully understood. Whole-genome sequencing of DNA samples from 71 Swedish patients with SLE and their healthy biological parents was performed to investigate the general genetic risk of SLE using known SLE GWAS risk loci identified using the ImmunoChip, variants in genes associated to monogenic SLE, and the mode of inheritance of SLE risk alleles in these families. A random forest model for predicting genetic risk for SLE showed that the SLE risk variants were mainly inherited from one of the parents. In the 71 patients, we detected a significant enrichment of ultra-rare (0.1%) missense and nonsense mutations in 22 genes known to cause monogenic forms of SLE. We identified one previously reported homozygous nonsense mutation in the C1QC (Complement C1q C Chain) gene, which explains the immunodeficiency and severe SLE phenotype of that patient. We also identified seven ultra-rare, coding heterozygous variants in five genes (C1S, DNASE1L3, DNASE1, IFIH1, and RNASEH2A) involved in monogenic SLE. Our findings indicate a complex contribution to the overall genetic risk of SLE by rare variants in genes associated with monogenic forms of SLE. The rare variants were inherited from the other parent than the one who passed on the more common risk variants leading to an increased genetic burden for SLE in the child. Higher frequency SLE risk variants are mostly passed from one of the parents to the offspring affected with SLE. In contrast, the other parent, in seven cases, contributed heterozygous rare variants in genes associated with monogenic forms of SLE, suggesting a larger impact of rare variants in SLE than hitherto reported.
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| 5. |
- Bolin, Karin, et al.
(författare)
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Association of STAT4 Polymorphism with Severe Renal Insufficiency in Lupus Nephritis
- 2013
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Ingår i: PLOS ONE. - : Public Library of Science. - 1932-6203. ; 8:12, s. 84450-
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Tidskriftsartikel (refereegranskat)abstract
- Lupus nephritis is a cause of significant morbidity in systemic lupus erythematosus (SLE) and its genetic background has not been completely clarified. The aim of this investigation was to analyze single nucleotide polymorphisms (SNPs) for association with lupus nephritis, its severe form proliferative nephritis and renal outcome, in two Swedish cohorts. Cohort I (n = 567 SLE cases, n = 512 controls) was previously genotyped for 5676 SNPs and cohort II (n = 145 SLE cases, n = 619 controls) was genotyped for SNPs in STAT4, IRF5, TNIP1 and BLK. Case-control and case-only association analyses for patients with lupus nephritis, proliferative nephritis and severe renal insufficiency were performed. In the case-control analysis of cohort I, four highly linked SNPs in STAT4 were associated with lupus nephritis with genome wide significance with p = 3.7x10(-9), OR 2.20 for the best SNP rs11889341. Strong signals of association between IRF5 and an HLA-DR3 SNP marker were also detected in the lupus nephritis case versus healthy control analysis (pless than0.0001). An additional six genes showed an association with lupus nephritis with pless than0.001 (PMS2, TNIP1, CARD11, ITGAM, BLK and IRAK1). In the case-only meta-analysis of the two cohorts, the STAT4 SNP rs7582694 was associated with severe renal insufficiency with p = 1.6x10(-3) and OR 2.22. We conclude that genetic variations in STAT4 predispose to lupus nephritis and a worse outcome with severe renal insufficiency.
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| 6. |
- Bolin, Karin, et al.
(författare)
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Variants in BANK1 are associated with lupus nephritis of European ancestry
- 2021
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Ingår i: Genes and Immunity. - : Springer Nature. - 1466-4879 .- 1476-5470. ; 22:3, s. 194-202
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Tidskriftsartikel (refereegranskat)abstract
- The genetic background of lupus nephritis (LN) has not been completely elucidated. We performed a case-only study of 2886 SLE patients, including 947 (33%) with LN. Renal biopsies were available from 396 patients. The discovery cohort (Sweden, n = 1091) and replication cohort 1 (US, n = 962) were genotyped on the Immunochip and replication cohort 2 (Denmark/Norway, n = 833) on a custom array. Patients with LN, proliferative nephritis, or LN with end-stage renal disease were compared with SLE without nephritis. Six loci were associated with LN (p < 1 × 10−4, NFKBIA, CACNA1S, ITGA1, BANK1, OR2Y, and ACER3) in the discovery cohort. Variants in BANK1 showed the strongest association with LN in replication cohort 1 (p = 9.5 × 10−4) and proliferative nephritis in a meta-analysis of discovery and replication cohort 1. There was a weak association between BANK1 and LN in replication cohort 2 (p = 0.052), and in the meta-analysis of all three cohorts the association was strengthened (p = 2.2 × 10−7). DNA methylation data in 180 LN patients demonstrated methylation quantitative trait loci (meQTL) effects between a CpG site and BANK1 variants. To conclude, we describe genetic variations in BANK1 associated with LN and evidence for genetic regulation of DNA methylation within the BANK1 locus. This indicates a role for BANK1 in LN pathogenesis.
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| 7. |
- Carlsson Almlöf, Jonas, et al.
(författare)
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Contributions of de novo variants to systemic lupus erythematosus
- 2021
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Ingår i: European Journal of Human Genetics. - : Springer Nature. - 1018-4813 .- 1476-5438. ; 29:1, s. 184-193
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Tidskriftsartikel (refereegranskat)abstract
- By performing whole-genome sequencing in a Swedish cohort of 71 parent-offspring trios, in which the child in each family is affected by systemic lupus erythematosus (SLE, OMIM 152700), we investigated the contribution of de novo variants to risk of SLE. We found de novo single nucleotide variants (SNVs) to be significantly enriched in gene promoters in SLE patients compared with healthy controls at a level corresponding to 26 de novo promoter SNVs more in each patient than expected. We identified 12 de novo SNVs in promoter regions of genes that have been previously implicated in SLE, or that have functions that could be of relevance to SLE. Furthermore, we detected three missense de novo SNVs, five de novo insertion-deletions, and three de novo structural variants with potential to affect the expression of genes that are relevant for SLE. Based on enrichment analysis, disease-affecting de novo SNVs are expected to occur in one-third of SLE patients. This study shows that de novo variants in promoters commonly contribute to the genetic risk of SLE. The fact that de novo SNVs in SLE were enriched to promoter regions highlights the importance of using whole-genome sequencing for identification of de novo variants.
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| 8. |
- Farias, Fabiana H. G., et al.
(författare)
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A rare regulatory variant in the MEF2D gene affects gene regulation and splicing and is associated with a SLE sub-phenotype in Swedish cohorts
- 2019
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Ingår i: European Journal of Human Genetics. - : Springer Science and Business Media LLC. - 1018-4813 .- 1476-5438. ; 27, s. 432-441
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Tidskriftsartikel (refereegranskat)abstract
- Systemic lupus erythematosus (SLE) is an autoimmune disorder with heterogeneous clinical presentation and complex etiology involving the interplay between genetic, epigenetic, environmental and hormonal factors. Many common SNPs identified by genome wide-association studies (GWAS) explain only a small part of the disease heritability suggesting the contribution from rare genetic variants, undetectable in GWAS, and complex epistatic interactions. Using targeted re-sequencing of coding and conserved regulatory regions within and around 215 candidate genes selected on the basis of their known role in autoimmunity and genes associated with canine immune-mediated diseases, we identified a rare regulatory variant rs200395694:G > T located in intron 4 of the MEF2D gene encoding the myocyte-specific enhancer factor 2D transcription factor and associated with SLE in Swedish cohorts (504 SLE patients and 839 healthy controls, p = 0.014, CI = 1.1-10). Fisher's exact test revealed an association between the genetic variant and a triad of disease manifestations including Raynaud, anti-U1-ribonucleoprotein (anti-RNP), and anti-Smith (anti-Sm) antibodies (p = 0.00037) among the patients. The DNA-binding activity of the allele was further studied by EMSA, reporter assays, and minigenes. The region has properties of an active cell-specific enhancer, differentially affected by the alleles of rs200395694:G > T. In addition, the risk allele exerts an inhibitory effect on the splicing of the alternative tissue-specific isoform, and thus may modify the target gene set regulated by this isoform. These findings emphasize the potential of dissecting traits of complex diseases and correlating them with rare risk alleles with strong biological effects.
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| 9. |
- Hallberg, Pär, et al.
(författare)
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Adipocyte-derived leucine aminopeptidase genotype and response to antihypertensive therapy
- 2003
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Ingår i: BMC Cardiovascular Disorders. - : Springer Science and Business Media LLC. - 1471-2261 .- 1471-2261. ; 18:3, s. 11-
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Tidskriftsartikel (refereegranskat)abstract
- BackgroundAdipocyte-derived leucine aminopeptidase (ALAP) is a recently identified member of the M1 family of zinc-metallopeptidases and is thought to play a role in blood pressure control through inactivation of angiotensin II and/or generation of bradykinin. The enzyme seems to be particularly abundant in the heart. Recently, the Arg528-encoding allele of the ALAP gene was shown to be associated with essential hypertension.MethodsWe evaluated the influence of this polymorphism on the change in left ventricular mass index in 90 patients with essential hypertension and echocardiographically diagnosed left ventricular hypertrophy, randomised in a double-blind study to receive treatment with either the angiotensin II type I receptor antagonist irbesartan or the beta1-adrenoceptor blocker atenolol for 48 weeks. Genyotyping was performed using minisequencing.ResultsAfter adjustment for potential covariates (blood pressure and left ventricular mass index at baseline, blood pressure change, age, sex, dose and added antihypertensive treatment), there was a marked difference between the Arg/Arg and Lys/Arg genotypes in patients treated with irbesartan; those with the Arg/Arg genotype responded on average with an almost two-fold greater regression of left ventricular mass index than patients with the Lys/Arg genotype (-30.1 g/m2 [3.6] vs -16.7 [4.5], p = 0.03).ConclusionsThe ALAP genotype seems to determine the degree of regression of left ventricular hypertrophy during antihypertensive treatment with the angiotensin II type I receptor antagonist irbesartan in patients with essential hypertension and left ventricular hypertrophy. This is the first report of a role for ALAP/aminopeptidases in left ventricular mass regulation, and suggests a new potential target for antihypertensive drugs.
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| 10. |
- Hallberg, Pär, et al.
(författare)
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Gender-specific association between preproendothelin-1 genotype and reduction of systolic blood pressure during antihypertensive treatment : results from the Swedish Irbesartan Left Ventricular Hypertrophy Investigation versus Atenolol (SILVHIA)
- 2004
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Ingår i: Clinical Cardiology. - : Wiley. - 0160-9289 .- 1932-8737. ; 27:5, s. 287-290
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Studies suggest that endothelin-1 contributes to the pathogenesis of hypertension. A G5665T gene polymorphism of preproendothelin-1 has been shown to be associated with higher blood pressure in overweight patients. No study has yet determined the effect of this polymorphism on the change in blood pressure during antihypertensive treatment.HYPOTHESIS:This study aimed to determine this effect in hypertensive patients with left ventricular (LV) hypertrophy during antihypertensive treatment with either irbesartan or atenolol.METHODS: We determined the preproendothelin-1 genotype using minisequencing in 102 patients with essential hypertension and LV hypertrophy verified by echocardiography, randomized in a double-blind fashion to treatment with either the AT1-receptor antagonist irbesartan or the beta1-adrenoceptor antagonist atenolol.RESULTS:The change in systolic blood pressure (SBP) after 12 weeks of treatment was related to the preproendothelin-1 genotype in men; after adjustment for potential covariates (age, blood pressure, and LV mass index at study entry, dose of irbesartan/atenolol, and type of treatment), those carrying the T-allele responded on average with a more than two-fold greater reduction than those with the G/G genotype (-21.9 mmHg [13.9] vs. -8.9 [2.3], p = 0.007). No significant differences in blood pressure change between G/G and carriers of the T-allele were seen among women.CONCLUSIONS:Our finding suggests a gender-specific relationship between the G5665T preproendothelin-1 polymorphism and change in SBP in response to antihypertensive treatment with irbesartan or atenolol, suggesting the endothelin pathway to be a common mechanism included in the hypertensive action of the drugs.
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