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1.
Int J Mol Sci ; 19(8)2018 Aug 08.
Artigo em Inglês | MEDLINE | ID: mdl-30096841

RESUMO

BANK1 is a susceptibility gene for several systemic autoimmune diseases in several populations. Using the genome-wide association study (GWAS) data from Europeans (EUR) and African Americans (AA), we performed an extensive fine mapping of ankyrin repeats 1 (BANK1). To increase the SNP density, we used imputation followed by univariate and conditional analysis, combined with a haplotypic and expression quantitative trait locus (eQTL) analysis. The data from Europeans showed that the associated region was restricted to a minimal and dependent set of SNPs covering introns two and three, and exon two. In AA, the signal found in the Europeans was split into two independent effects. All of the major risk associated SNPs were eQTLs, and the risks were associated with an increased BANK1 gene expression. Functional annotation analysis revealed the enrichment of repressive B cell epigenomic marks (EZH2 and H3K27me3) and a strong enrichment of splice junctions. Furthermore, one eQTL located in intron two, rs13106926, was found within the binding site for RUNX3, a transcriptional activator. These results connect the local genome topography, chromatin structure, and the regulatory landscape of BANK1 with co-transcriptional splicing of exon two. Our data defines a minimal set of risk associated eQTLs predicted to be involved in the expression of BANK1 modulated through epigenetic regulation and splicing. These findings allow us to suggest that the increased expression of BANK1 will have an impact on B-cell mediated disease pathways.

2.
Hum Mol Genet ; 2018 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-29912393

RESUMO

Systemic Lupus Erythematosus (SLE or lupus) (OMIM: 152700) is a chronic autoimmune disease with debilitating inflammation that affects multiple organ systems. The STAT1-STAT4 locus is one of the first and most highly-replicated genetic loci associated with lupus risk. We performed a fine-mapping study to identify plausible causal variants within the STAT1-STAT4 locus associated with increased lupus disease risk. Using complementary frequentist and Bayesian approaches in trans-ancestral Discovery and Replication cohorts, we found one variant whose association with lupus risk is supported across ancestries in both the Discovery and Replication cohorts: rs11889341. In B cell lines from patients with lupus and healthy controls, the lupus risk allele of rs11889341 was associated with increased STAT1 expression. We demonstrated that the transcription factor HMGA1, a member of the HMG transcription factor family with an AT-hook DNA-binding domain, has enriched binding to the risk allele compared to the non-risk allele of rs11889341. We identified a genotype-dependent repressive element in the DNA within the intron of STAT4 surrounding rs11889341. Consistent with expression quantitative trait locus (eQTL) analysis, the lupus risk allele of rs11889341 decreased the activity of this putative repressor. Altogether, we present a plausible molecular mechanism for increased lupus risk at the STAT1-STAT4 locus in which the risk allele of rs11889341, the most probable causal variant, leads to elevated STAT1 expression in B cells due to decreased repressor activity mediated by increased binding of HMGA1.

3.
Arthritis Rheumatol ; 70(6): 957-962, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29426059

RESUMO

OBJECTIVE: Juvenile idiopathic arthritis (JIA) comprises 7 heterogeneous categories of chronic childhood arthritides. Approximately 5% of children with JIA have rheumatoid factor (RF)-positive arthritis, which phenotypically resembles adult rheumatoid arthritis (RA). Our objective was to compare and contrast the genetics of RF-positive polyarticular JIA with those of RA and selected other JIA categories, to more fully understand the pathophysiologic relationships of inflammatory arthropathies. METHODS: Patients with RF-positive polyarticular JIA (n = 340) and controls (n = 14,412) were genotyped using the Immunochip array. Single-nucleotide polymorphisms were tested for association using a logistic regression model adjusting for admixture proportions. We calculated weighted genetic risk scores (wGRS) of reported RA and JIA risk loci, and we compared the ability of these wGRS to predict RF-positive polyarticular JIA. RESULTS: As expected, the HLA region was strongly associated with RF-positive polyarticular JIA (P = 5.51 × 10-31 ). Nineteen of 44 RA risk loci and 6 of 27 oligoarticular/RF-negative polyarticular JIA risk loci were associated with RF-positive polyarticular JIA (P < 0.05). The RA wGRS predicted RF-positive polyarticular JIA (area under the curve [AUC] 0.71) better than did the oligoarticular/RF-negative polyarticular JIA wGRS (AUC 0.59). The genetic profile of patients with RF-positive polyarticular JIA was more similar to that of RA patients with age at onset 16-29 years than to that of RA patients with age at onset ≥70 years. CONCLUSION: RF-positive polyarticular JIA is genetically more similar to adult RA than to the most common JIA categories and thus appears to be a childhood-onset presentation of autoantibody-positive RA. These findings suggest common disease mechanisms, which could lead to novel therapeutic targets and shared treatment strategies.

4.
Arthritis Rheumatol ; 69(11): 2170-2174, 2017 11.
Artigo em Inglês | MEDLINE | ID: mdl-29045069

RESUMO

OBJECTIVE: Fetal exposure to maternal anti-SSA/Ro antibodies is necessary but not sufficient for the development of autoimmune congenital heart block (CHB), suggesting that other factors, such as fetal genetic predisposition, are important. Given the previously described association between major histocompatibility complex alleles and CHB risk, we undertook the present study to test the hypothesis that a variant form of HLA-C Asn80Lys, which binds with high affinity to an inhibitory killer cell immunoglobulin-like receptor (KIR) and thus renders natural killer (NK) cells incapable of restricting inflammation, contributes to the development of CHB. METHODS: Members of 192 pedigrees in the US and Europe (194 cases of CHB, 91 unaffected siblings, 152 fathers, 167 mothers) and 1,073 out-of-study controls were genotyped on the Immunochip single-nucleotide polymorphism microarray. Imputation was used to identify associations at HLA-C Asn80Lys (Asn, C1; Lys, C2) and KIR. Tests for association were performed using logistic regression. McNemar's test and the pedigree disequilibrium test (PDT) were used for matched analyses between affected and unaffected children. RESULTS: Compared with out-of-study controls of the same sex, the C2 allele was less frequent in the mothers (odds ratio [OR] 0.63, P = 0.0014) and more frequent in the fathers (OR 1.40, P = 0.0123), yielding a significant sex-by-C2 interaction (P = 0.0002). The C2 allele was more frequent in affected siblings than in unaffected siblings (OR 3.67, P = 0.0025), which was consistent with the PDT results (P = 0.016); these results were observed in both sexes and across the US and European cohorts. There was no difference in the frequency of the inhibitory KIR genotype (KIR AA) between affected and unaffected children (P = 0.55). CONCLUSION: These data establish C2 as a novel genetic risk factor associated with CHB. This observation supports a model in which fetuses with C2 ligand expression and maternal anti-SSA/Ro positivity may have impaired NK cell surveillance, resulting in unchecked cardiac inflammation and scarring.


Assuntos
Antígenos HLA-C/genética , Bloqueio Cardíaco/congênito , Anticorpos Antinucleares/imunologia , Estudos de Casos e Controles , Ensaio de Imunoadsorção Enzimática , Europa (Continente) , Pai , Feminino , Genótipo , Bloqueio Cardíaco/genética , Bloqueio Cardíaco/imunologia , Humanos , Recém-Nascido , Modelos Logísticos , Masculino , Mães , Razão de Chances , Linhagem , Polimorfismo Genético , Polimorfismo de Nucleotídeo Único , Fatores Sexuais , Irmãos , Estados Unidos
5.
Arthritis Rheumatol ; 69(11): 2222-2232, 2017 11.
Artigo em Inglês | MEDLINE | ID: mdl-28719732

RESUMO

OBJECTIVE: Juvenile idiopathic arthritis (JIA) is the most common childhood rheumatic disease and has a strong genomic component. To date, JIA genetic association studies have had limited sample sizes, used heterogeneous patient populations, or included only candidate regions. The aim of this study was to identify new associations between JIA patients with oligoarticular disease and those with IgM rheumatoid factor (RF)-negative polyarticular disease, which are clinically similar and the most prevalent JIA disease subtypes. METHODS: Three cohorts comprising 2,751 patients with oligoarticular or RF-negative polyarticular JIA were genotyped using the Affymetrix Genome-Wide SNP Array 6.0 or the Illumina HumanCoreExome-12+ Array. Overall, 15,886 local and out-of-study controls, typed on these platforms or the Illumina HumanOmni2.5, were used for association analyses. High-quality single-nucleotide polymorphisms (SNPs) were used for imputation to 1000 Genomes prior to SNP association analysis. RESULTS: Meta-analysis showed evidence of association (P < 1 × 10-6 ) at 9 regions: PRR9_LOR (P = 5.12 × 10-8 ), ILDR1_CD86 (P = 6.73 × 10-8 ), WDFY4 (P = 1.79 × 10-7 ), PTH1R (P = 1.87 × 10-7 ), RNF215 (P = 3.09 × 10-7 ), AHI1_LINC00271 (P = 3.48 × 10-7 ), JAK1 (P = 4.18 × 10-7 ), LINC00951 (P = 5.80 × 10-7 ), and HBP1 (P = 7.29 × 10-7 ). Of these, PRR9_LOR, ILDR1_CD86, RNF215, LINC00951, and HBP1 were shown, for the first time, to be autoimmune disease susceptibility loci. Furthermore, associated SNPs included cis expression quantitative trait loci for WDFY4, CCDC12, MTP18, SF3A1, AHI1, COG5, HBP1, and GPR22. CONCLUSION: This study provides evidence of both unique JIA risk loci and risk loci overlapping between JIA and other autoimmune diseases. These newly associated SNPs are shown to influence gene expression, and their bounding regions tie into molecular pathways of immunologic relevance. Thus, they likely represent regions that contribute to the pathology of oligoarticular JIA and RF-negative polyarticular JIA.


Assuntos
Artrite Juvenil/genética , Proteínas Adaptadoras de Transdução de Sinal/genética , Proteínas Adaptadoras de Transporte Vesicular/genética , Antígeno B7-2/genética , Criança , Pré-Escolar , Feminino , Predisposição Genética para Doença , Estudo de Associação Genômica Ampla , Proteínas de Grupo de Alta Mobilidade/genética , Humanos , Lactente , Peptídeos e Proteínas de Sinalização Intracelular/genética , Janus Quinase 1/genética , Masculino , Proteínas Mitocondriais/genética , Polimorfismo de Nucleotídeo Único , Proteínas/genética , Locos de Características Quantitativas/genética , Fatores de Processamento de RNA/genética , Receptor Tipo 1 de Hormônio Paratireóideo/genética , Receptores de Superfície Celular/genética , Receptores Acoplados a Proteínas-G/genética , Proteínas Repressoras/genética
6.
Nat Commun ; 8: 16021, 2017 07 17.
Artigo em Inglês | MEDLINE | ID: mdl-28714469

RESUMO

Systemic lupus erythematosus (SLE) is an autoimmune disease with marked gender and ethnic disparities. We report a large transancestral association study of SLE using Immunochip genotype data from 27,574 individuals of European (EA), African (AA) and Hispanic Amerindian (HA) ancestry. We identify 58 distinct non-HLA regions in EA, 9 in AA and 16 in HA (∼50% of these regions have multiple independent associations); these include 24 novel SLE regions (P<5 × 10-8), refined association signals in established regions, extended associations to additional ancestries, and a disentangled complex HLA multigenic effect. The risk allele count (genetic load) exhibits an accelerating pattern of SLE risk, leading us to posit a cumulative hit hypothesis for autoimmune disease. Comparing results across the three ancestries identifies both ancestry-dependent and ancestry-independent contributions to SLE risk. Our results are consistent with the unique and complex histories of the populations sampled, and collectively help clarify the genetic architecture and ethnic disparities in SLE.

7.
Am J Hum Genet ; 96(5): 731-9, 2015 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-25865496

RESUMO

Genetic variants at chromosomal region 11q23.3, near the gene ETS1, have been associated with systemic lupus erythematosus (SLE), or lupus, in independent cohorts of Asian ancestry. Several recent studies have implicated ETS1 as a critical driver of immune cell function and differentiation, and mice deficient in ETS1 develop an SLE-like autoimmunity. We performed a fine-mapping study of 14,551 subjects from multi-ancestral cohorts by starting with genotyped variants and imputing to all common variants spanning ETS1. By constructing genetic models via frequentist and Bayesian association methods, we identified 16 variants that are statistically likely to be causal. We functionally assessed each of these variants on the basis of their likelihood of affecting transcription factor binding, miRNA binding, or chromatin state. Of the four variants that we experimentally examined, only rs6590330 differentially binds lysate from B cells. Using mass spectrometry, we found more binding of the transcription factor signal transducer and activator of transcription 1 (STAT1) to DNA near the risk allele of rs6590330 than near the non-risk allele. Immunoblot analysis and chromatin immunoprecipitation of pSTAT1 in B cells heterozygous for rs6590330 confirmed that the risk allele increased binding to the active form of STAT1. Analysis with expression quantitative trait loci indicated that the risk allele of rs6590330 is associated with decreased ETS1 expression in Han Chinese, but not other ancestral cohorts. We propose a model in which the risk allele of rs6590330 is associated with decreased ETS1 expression and increases SLE risk by enhancing the binding of pSTAT1.


Assuntos
Predisposição Genética para Doença , Lúpus Eritematoso Sistêmico/genética , Proteína Proto-Oncogênica c-ets-1/genética , Fator de Transcrição STAT1/genética , Alelos , Animais , Grupo com Ancestrais do Continente Asiático , Teorema de Bayes , Genótipo , Haplótipos , Humanos , Camundongos , Ligação Proteica , Proteína Proto-Oncogênica c-ets-1/metabolismo , Fator de Transcrição STAT1/metabolismo
8.
Front Genet ; 5: 450, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25620976

RESUMO

Genome wide association studies have identified variants in PXK that confer risk for humoral autoimmune diseases, including systemic lupus erythematosus (SLE or lupus), rheumatoid arthritis and more recently systemic sclerosis. While PXK is involved in trafficking of epidermal growth factor Receptor (EGFR) in COS-7 cells, mechanisms linking PXK to lupus pathophysiology have remained undefined. In an effort to uncover the mechanism at this locus that increases lupus-risk, we undertook a fine-mapping analysis in a large multi-ancestral study of lupus patients and controls. We define a large (257kb) common haplotype marking a single causal variant that confers lupus risk detected only in European ancestral populations and spans the promoter through the 3' UTR of PXK. The strongest association was found at rs6445972 with P < 4.62 × 10(-10), OR 0.81 (0.75-0.86). Using stepwise logistic regression analysis, we demonstrate that one signal drives the genetic association in the region. Bayesian analysis confirms our results, identifying a 95% credible set consisting of 172 variants spanning 202 kb. Functionally, we found that PXK operates on the B-cell antigen receptor (BCR); we confirmed that PXK influenced the rate of BCR internalization. Furthermore, we demonstrate that individuals carrying the risk haplotype exhibited a decreased rate of BCR internalization, a process known to impact B cell survival and cell fate. Taken together, these data define a new candidate mechanism for the genetic association of variants around PXK with lupus risk and highlight the regulation of intracellular trafficking as a genetically regulated pathway mediating human autoimmunity.

9.
Nat Genet ; 45(6): 664-9, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23603761

RESUMO

We used the Immunochip array to analyze 2,816 individuals with juvenile idiopathic arthritis (JIA), comprising the most common subtypes (oligoarticular and rheumatoid factor-negative polyarticular JIA), and 13,056 controls. We confirmed association of 3 known JIA risk loci (the human leukocyte antigen (HLA) region, PTPN22 and PTPN2) and identified 14 loci reaching genome-wide significance (P < 5 × 10(-8)) for the first time. Eleven additional new regions showed suggestive evidence of association with JIA (P < 1 × 10(-6)). Dense mapping of loci along with bioinformatics analysis refined the associations to one gene in each of eight regions, highlighting crucial pathways, including the interleukin (IL)-2 pathway, in JIA disease pathogenesis. The entire Immunochip content, the HLA region and the top 27 loci (P < 1 × 10(-6)) explain an estimated 18, 13 and 6% of the risk of JIA, respectively. In summary, this is the largest collection of JIA cases investigated so far and provides new insight into the genetic basis of this childhood autoimmune disease.


Assuntos
Artrite Juvenil/genética , Adulto , Artrite Juvenil/imunologia , Estudos de Casos e Controles , Criança , Mapeamento Cromossômico , Frequência do Gene , Loci Gênicos , Predisposição Genética para Doença , Estudo de Associação Genômica Ampla , Genótipo , Humanos , Interleucinas/genética , Desequilíbrio de Ligação , Anotação de Sequência Molecular , Polimorfismo de Nucleotídeo Único , Receptores CCR/genética , Receptores de Interleucina/genética , Fatores de Risco
10.
Neurobiol Aging ; 34(1): 357.e7-19, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22959728

RESUMO

Amyotrophic lateral sclerosis (ALS) is the third most common adult-onset neurodegenerative disease. Individuals with ALS rapidly progress to paralysis and die from respiratory failure within 3 to 5 years after symptom onset. Epidemiological factors explain only a modest amount of the risk for ALS. However, there is growing evidence of a strong genetic component to both familial and sporadic ALS risk. The International Consortium on Amyotrophic Lateral Sclerosis Genetics was established to bring together existing genome-wide association cohorts and identify sporadic ALS susceptibility and age at symptom onset loci. Here, we report the results of a meta-analysis of the International Consortium on Amyotrophic Lateral Sclerosis Genetics genome-wide association samples, consisting of 4243 ALS cases and 5112 controls from 13 European ancestry cohorts from across the United States and Europe. Eight genomic regions provided evidence of association with ALS, including 9p21.2 (rs3849942, odds ratio [OR] = 1.21; p = 4.41 × 10(-7)), 17p11.2 (rs7477, OR = 1.30; p = 2.89 × 10(-7)), and 19p13 (rs12608932, OR = 1.37, p = 1.29 × 10(-7)). Six genomic regions were associated with age at onset of ALS. The strongest evidence for an age of onset locus was observed at 1p34.1, with comparable evidence at rs3011225 (R(2)(partial) = 0.0061; p = 6.59 × 10(-8)) and rs803675 (R(2)(partial) = 0.0060; p = 6.96 × 10(-8)). These associations were consistent across all 13 cohorts. For rs3011225, individuals with at least 1 copy of the minor allele had an earlier average age of onset of over 2 years. Identifying the underlying pathways influencing susceptibility to and age at onset of ALS may provide insight into the pathogenic mechanisms and motivate new pharmacologic targets for this fatal neurodegenerative disease.


Assuntos
Idade de Início , Esclerose Amiotrófica Lateral/genética , Cromossomos Humanos Par 1/genética , Predisposição Genética para Doença , Idoso , Idoso de 80 Anos ou mais , Esclerose Amiotrófica Lateral/epidemiologia , Europa (Continente)/epidemiologia , Feminino , Genótipo , Humanos , Masculino , Metanálise como Assunto , Pessoa de Meia-Idade , Polimorfismo de Nucleotídeo Único , Estados Unidos/epidemiologia
11.
Ann Rheum Dis ; 72(3): 437-44, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22904263

RESUMO

OBJECTIVES: The Xq28 region containing IRAK1 and MECP2 has been identified as a risk locus for systemic lupus erythematosus (SLE) in previous genetic association studies. However, due to the strong linkage disequilibrium between IRAK1 and MECP2, it remains unclear which gene is affected by the underlying causal variant(s) conferring risk of SLE. METHODS: We fine-mapped ≥136 SNPs in a ∼227 kb region on Xq28, containing IRAK1, MECP2 and seven adjacent genes (L1CAM, AVPR2, ARHGAP4, NAA10, RENBP, HCFC1 and TMEM187), for association with SLE in 15 783 case-control subjects derived from four different ancestral groups. RESULTS: Multiple SNPs showed strong association with SLE in European Americans, Asians and Hispanics at p<5×10(-8) with consistent association in subjects with African ancestry. Of these, six SNPs located in the TMEM187-IRAK1-MECP2 region captured the underlying causal variant(s) residing in a common risk haplotype shared by all four ancestral groups. Among them, rs1059702 best explained the Xq28 association signals in conditional testings and exhibited the strongest p value in transancestral meta-analysis (p(meta )= 1.3×10(-27), OR=1.43), and thus was considered to be the most likely causal variant. The risk allele of rs1059702 results in the amino acid substitution S196F in IRAK1 and had previously been shown to increase NF-κB activity in vitro. We also found that the homozygous risk genotype of rs1059702 was associated with lower mRNA levels of MECP2, but not IRAK1, in SLE patients (p=0.0012) and healthy controls (p=0.0064). CONCLUSIONS: These data suggest contributions of both IRAK1 and MECP2 to SLE susceptibility.


Assuntos
Cromossomos Humanos X/genética , Grupos de Populações Continentais/genética , Quinases Associadas a Receptores de Interleucina-1/genética , Lúpus Eritematoso Sistêmico/genética , Proteína 2 de Ligação a Metil-CpG/genética , Sequência de Bases , Mapeamento Cromossômico , Predisposição Genética para Doença/genética , Genótipo , Haplótipos , Humanos , Dados de Sequência Molecular , Polimorfismo de Nucleotídeo Único , Reação em Cadeia da Polimerase em Tempo Real , Fatores de Risco
12.
Arthritis Rheum ; 64(12): 4060-5, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22886516

RESUMO

OBJECTIVE: The proposed pathogenesis of the cardiac manifestations of neonatal lupus (cardiac-NL) involves maternal autoantibodies to the RNPs SSA/Ro and SSB/La, enhanced by as-yet-unknown factors that likely involve dysregulation of both inflammatory and fibrotic fetal responses. This study was designed to improve the power to detect specific associations in genes with candidate biologic functions. METHODS: Using data from our genome-wide association study of 116 Caucasian children with cardiac-NL and 3,351 Caucasian controls, we tested for enrichment of single-nucleotide polymorphism (SNP) associations in genes with candidate biologic functions related to fibrosis, immune function, apoptosis, T cell function, cell infiltration, innate immune cell function, interferon, Toll-like receptors, and calcium channels. After linkage disequilibrium pruning and exclusion of the extended HLA region, a total of 15,103 SNPs in 3,068 genes remained. RESULTS: A highly significant enrichment of P values was observed for genes related to fibrosis (P = 2.27 × 10(-9) ), apoptosis (P = 7.67 × 10(-7) ), and innate immune cell (P = 2.53 × 10(-6) ), immune (P = 5.01 × 10(-4) ), T cell (P = 2.23 × 10(-4) ), and interferon functions (P = 1.64 × 10(-3) ). The most significant non-HLA associations included the sialyltransferase gene ST8SIA2 (rs1487982; odds ratio 2.20 [95% confidence interval 1.52-3.19], P = 3.37 × 10(-5) ), the integrin gene ITGA1 (rs2432143; odds ratio 2.31 [95% confidence interval 1.54-3.45], P = 4.54 × 10(-5) ), and the complement regulator gene CSMD1 (rs7002001; odds ratio 2.41 [95% confidence interval 1.57-3.72], P = 6.33 × 10(-5) ). CONCLUSION: This study identified novel candidate genes associated with cardiac-NL and highlights the value of studying this cohort for advancing knowledge regarding the genetic etiology of this syndrome. Identification of causal alleles is expected to provide critical insight into the molecular mechanisms responsible for linking maternal autoantibodies to cardiac scarring in these fetuses/neonates.


Assuntos
Apoptose/genética , Imunidade Inata/genética , Lúpus Eritematoso Sistêmico/congênito , Miocárdio/patologia , Estudos de Casos e Controles , Fibrose/genética , Estudo de Associação Genômica Ampla , Humanos , Recém-Nascido , Desequilíbrio de Ligação/genética , Lúpus Eritematoso Sistêmico/genética , Polimorfismo de Nucleotídeo Único/genética
13.
Arthritis Rheum ; 64(11): 3687-94, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22886787

RESUMO

OBJECTIVE: American Indian-Europeans, Asians, and African Americans have an excess morbidity from systemic lupus erythematosus (SLE) and a higher prevalence of lupus nephritis than do Caucasians. The aim of this study was to analyze the relationship between genetic ancestry and sociodemographic characteristics and clinical features in a large cohort of American Indian-European SLE patients. METHODS: A total of 2,116 SLE patients of American Indian-European origin and 4,001 SLE patients of European descent for whom we had clinical data were included in the study. Genotyping of 253 continental ancestry-informative markers was performed on the Illumina platform. Structure and Admixture software were used to determine genetic ancestry proportions of each individual. Logistic regression was used to test the association between genetic ancestry and sociodemographic and clinical characteristics. Odds ratios (ORs) were calculated with 95% confidence intervals (95% CIs). RESULTS: The average American Indian genetic ancestry of 2,116 SLE patients was 40.7%. American Indian genetic ancestry conferred increased risks of renal involvement (P < 0.0001, OR 3.50 [95% CI 2.63- 4.63]) and early age at onset (P < 0.0001). American Indian ancestry protected against photosensitivity (P < 0.0001, OR 0.58 [95% CI 0.44-0.76]), oral ulcers (P < 0.0001, OR 0.55 [95% CI 0.42-0.72]), and serositis (P < 0.0001, OR 0.56 [95% CI 0.41-0.75]) after adjustment for age, sex, and age at onset. However, age and sex had stronger effects than genetic ancestry on malar rash, discoid rash, arthritis, and neurologic involvement. CONCLUSION: In general, American Indian genetic ancestry correlates with lower sociodemographic status and increases the risk of developing renal involvement and SLE at an earlier age.


Assuntos
Grupo com Ancestrais do Continente Europeu/genética , Índios Norte-Americanos/genética , Índios Sul-Americanos/genética , Lúpus Eritematoso Sistêmico/etnologia , Lúpus Eritematoso Sistêmico/genética , Adolescente , Adulto , Criança , Grupo com Ancestrais do Continente Europeu/estatística & dados numéricos , Feminino , Predisposição Genética para Doença/etnologia , Genótipo , Humanos , Índios Norte-Americanos/estatística & dados numéricos , Índios Sul-Americanos/estatística & dados numéricos , Nefrite Lúpica/etnologia , Nefrite Lúpica/genética , Masculino , Pessoa de Meia-Idade , Morbidade , Prevalência , Fatores de Risco , Fatores Socioeconômicos , Adulto Jovem
14.
Arthritis Rheum ; 64(11): 3695-705, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22833143

RESUMO

OBJECTIVE: Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by autoantibody production and altered type I interferon expression. Genetic surveys and genome-wide association studies have identified >30 SLE susceptibility genes. One of these genes, TNIP1, encodes the ABIN1 protein. ABIN1 functions in the immune system by restricting NF-κB signaling. The present study was undertaken to investigate the genetic factors that influence association with SLE in genes that regulate the NF-κB pathway. METHODS: We analyzed a dense set of genetic markers spanning TNIP1 and TAX1BP1, as well as the TNIP1 homolog TNIP2, in case-control populations of diverse ethnic origins. TNIP1, TNIP2, and TAX1BP1 were fine-mapped in a total of 8,372 SLE cases and 7,492 healthy controls from European-ancestry, African American, Hispanic, East Asian, and African American Gullah populations. Levels of TNIP1 messenger RNA (mRNA) and ABIN1 protein in Epstein-Barr virus-transformed human B cell lines were analyzed by quantitative reverse transcription-polymerase chain reaction and Western blotting, respectively. RESULTS: We found significant associations between SLE and genetic variants within TNIP1, but not in TNIP2 or TAX1BP1. After resequencing and imputation, we identified 2 independent risk haplotypes within TNIP1 in individuals of European ancestry that were also present in African American and Hispanic populations. Levels of TNIP1 mRNA and ABIN1 protein were reduced among subjects with these haplotypes, suggesting that they harbor hypomorphic functional variants that influence susceptibility to SLE by restricting ABIN1 expression. CONCLUSION: Our results confirm the association signals between SLE and TNIP1 variants in multiple populations and provide new insight into the mechanism by which TNIP1 variants may contribute to SLE pathogenesis.


Assuntos
Proteínas de Ligação a DNA/genética , Haplótipos/genética , Lúpus Eritematoso Sistêmico/etnologia , Lúpus Eritematoso Sistêmico/genética , Proteínas Adaptadoras de Transdução de Sinal/genética , Afro-Americanos/genética , Afro-Americanos/estatística & dados numéricos , Americanos Asiáticos/genética , Americanos Asiáticos/estatística & dados numéricos , Linfócitos B/citologia , Linhagem Celular Transformada , Grupo com Ancestrais do Continente Europeu/genética , Grupo com Ancestrais do Continente Europeu/estatística & dados numéricos , Feminino , Marcadores Genéticos/genética , Predisposição Genética para Doença/etnologia , Predisposição Genética para Doença/genética , Hispano-Americanos/genética , Hispano-Americanos/estatística & dados numéricos , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/genética , Masculino , Proteínas de Neoplasias/genética , Polimorfismo de Nucleotídeo Único/genética , Fatores de Risco , Estados Unidos/epidemiologia
15.
Arthritis Rheum ; 64(8): 2781-91, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22354554

RESUMO

OBJECTIVE: In a genome-wide association study of Caucasian patients with juvenile idiopathic arthritis (JIA), we have previously described findings limited to autoimmunity loci shared by JIA and other diseases. The present study was undertaken to identify novel JIA-predisposing loci using genome-wide approaches. METHODS: The discovery cohort consisted of Caucasian JIA cases (n = 814) and local controls (n = 658) genotyped on the Affymetrix Genome-Wide SNP 6.0 Array, along with 2,400 out-of-study controls. In a replication study, we genotyped 10 single-nucleotide polymorphisms (SNPs) in 1,744 cases and 7,010 controls from the US and Europe. RESULTS: Analysis within the discovery cohort provided evidence of associations at 3q13 within C3orf1 and near CD80 (rs4688011) (odds ratio [OR] 1.37, P = 1.88 × 10(-6) ) and at 10q21 near JMJD1C (rs647989 [OR 1.59, P = 6.1 × 10(-8) ], rs12411988 [OR 1.57, P = 1.16 × 10(-7) ], and rs10995450 [OR 1.31, P = 6.74 × 10(-5) ]). Meta-analysis provided further evidence of association for these 4 SNPs (P = 3.6 × 10(-7) for rs4688011, P = 4.33 × 10(-5) for rs6479891, P = 2.71 × 10(-5) for rs12411988, and P = 5.39 × 10(-5) for rs10995450). Gene expression data on 68 JIA cases and 23 local controls showed cis expression quantitative trait locus associations for C3orf1 SNP rs4688011 (P = 0.024 or P = 0.034, depending on the probe set) and JMJD1C SNPs rs6479891 and rs12411988 (P = 0.01 or P = 0.04, depending on the probe set and P = 0.008, respectively). Using a variance component liability model, it was estimated that common SNP variation accounts for approximately one-third of JIA susceptibility. CONCLUSION: Genetic association results and correlated gene expression findings provide evidence of JIA association at 3q13 and suggest novel genes as plausible candidates in disease pathology.


Assuntos
Artrite Juvenil/genética , Cromossomos Humanos Par 3/genética , Predisposição Genética para Doença/genética , Estudo de Associação Genômica Ampla , Artrite Juvenil/etnologia , Estudos de Casos e Controles , Criança , Pré-Escolar , Estudos de Coortes , Grupo com Ancestrais do Continente Europeu/etnologia , Feminino , Predisposição Genética para Doença/etnologia , Genótipo , Humanos , Masculino , Polimorfismo de Nucleotídeo Único/genética
16.
Arthritis Rheum ; 64(3): 931-9, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22031281

RESUMO

OBJECTIVE: Neonatal lupus (NL) occurs in fetuses exposed to maternal anti-SSA/Ro and/or anti-SSB/La antibodies, although the mothers themselves may not manifest any clinical disease. A focus on transmission of risk factors for NL from maternal grandparents to mothers of children with NL may yield dividends toward understanding the aggregation of autoantibodies and genetic factors in affected families. This study was perforned to determine the role of maternal grandparents in the development of the autoimmune phenotype of mothers of children with NL. METHODS: Fifty-one mothers of children with cardiac and/or cutaneous NL, 48 maternal grandmothers, and 35 maternal grandfathers in the Research Registry for Neonatal Lupus were interrogated for clinical symptoms by questionnaire and underwent laboratory assessments, including determination of anti-SSA/Ro and anti-SSB/La antibody status (by enzyme-linked immunosorbent assay) and genotype at rs1800629 (TNFα) and rs7775397 (C6orf10) (allelic discrimination). The transmission disequilibrium test (TDT) was computed to test for nonrandom transmission from maternal grandparents to mothers of children with NL. RESULTS: The common phenotypic feature in mothers of children with NL was the autoantibody and not the clinical profile; 7 had lupus, 14 had Sjögren's syndrome, 7 had both, and 23 were asymptomatic. Mothers of children with NL were significantly enriched for the risk alleles at both TNFα and C6orf10. The grandparents of children with NL carried minimal burden for autoimmune disease or abnormal antibody production and were not enriched in the genetic risk factors. However, the TDT analysis showed significant excess transmission of the risk alleles at both TNFα (odds ratio [OR] 6.67, P = 3.93 × 10(-4) ) and C6orf10 (OR 35.0, P = 3.74 × 10(-5) ) to mothers of children with NL. CONCLUSION: Mothers of children with NL are enriched for the TNFα and C6orf10 risk alleles, which are preferentially inherited from the asymptomatic maternal grandparents. These findings support the hypothesis that the development of NL and genetic etiology are multigenerational.


Assuntos
Doenças Assintomáticas , Cromossomos Humanos Par 6 , Predisposição Genética para Doença , Lúpus Eritematoso Sistêmico/genética , Adulto , Idoso , Família , Características da Família , Feminino , Doenças Genéticas Inatas , Genótipo , Humanos , Recém-Nascido , Lúpus Eritematoso Sistêmico/congênito , Lúpus Eritematoso Sistêmico/diagnóstico , Masculino , Pessoa de Meia-Idade , Linhagem , Fatores de Risco
17.
Dig Dis Sci ; 57(4): 952-7, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22160635

RESUMO

BACKGROUND: The peroxisome proliferator activated receptor-gamma (PPARG) is a nuclear receptor that regulates adipocyte differentiation, insulin sensitivity and lipid metabolism, thus, it represents a good candidate gene for non-alcoholic fatty liver disease (NAFLD). PURPOSE AND METHOD: We investigated the association of two PPARG variants (Pro12Ala and C1431T) with NAFLD and its histological features. DNA was extracted from 274 archived, formalin-fixed liver biopsy specimens from 212 patients with NAFLD and 62 controls with normal liver histology. RESULTS: Individual SNPs did not show significant association with NAFLD or its histological features. A haplotype comprised of both minor alleles (GT) was less enriched whereas a haplotype comprised of the two major alleles (CC) was more enriched in subjects with NAFLD compared to controls [9.3% vs. 28.1% for GT (P = 0.001, OR 0.26 (range 0.14-0.48) and 80.4% vs. 64.8% for CC (P = 0.037, OR 2.23 (range 1.30-3.81)]. Both haplotypes were significantly associated with steatosis and fibrosis. The GT haplotype was also associated with lobular inflammation. CONCLUSIONS: Genetic variation in PPARG is associated with NAFLD, and the GT haplotype is associated with inflammatory and fibrotic changes that denote histologically advanced NAFLD.


Assuntos
Fígado Gorduroso/genética , PPAR gama/genética , Polimorfismo de Nucleotídeo Único , Adulto , Fígado Gorduroso/patologia , Feminino , Frequência do Gene , Genótipo , Haplótipos , Humanos , Fígado/patologia , Masculino , Pessoa de Meia-Idade , Hepatopatia Gordurosa não Alcoólica
18.
PLoS Genet ; 7(5): e1002079, 2011 May.
Artigo em Inglês | MEDLINE | ID: mdl-21637784

RESUMO

Systemic lupus erythematosus (SLE), a complex polygenic autoimmune disease, is associated with increased complement activation. Variants of genes encoding complement regulator factor H (CFH) and five CFH-related proteins (CFHR1-CFHR5) within the chromosome 1q32 locus linked to SLE, have been associated with multiple human diseases and may contribute to dysregulated complement activation predisposing to SLE. We assessed 60 SNPs covering the CFH-CFHRs region for association with SLE in 15,864 case-control subjects derived from four ethnic groups. Significant allelic associations with SLE were detected in European Americans (EA) and African Americans (AA), which could be attributed to an intronic CFH SNP (rs6677604, in intron 11, P(meta) = 6.6×10(-8), OR = 1.18) and an intergenic SNP between CFHR1 and CFHR4 (rs16840639, P(meta) = 2.9×10(-7), OR = 1.17) rather than to previously identified disease-associated CFH exonic SNPs, including I62V, Y402H, A474A, and D936E. In addition, allelic association of rs6677604 with SLE was subsequently confirmed in Asians (AS). Haplotype analysis revealed that the underlying causal variant, tagged by rs6677604 and rs16840639, was localized to a ~146 kb block extending from intron 9 of CFH to downstream of CFHR1. Within this block, the deletion of CFHR3 and CFHR1 (CFHR3-1Δ), a likely causal variant measured using multiplex ligation-dependent probe amplification, was tagged by rs6677604 in EA and AS and rs16840639 in AA, respectively. Deduced from genotypic associations of tag SNPs in EA, AA, and AS, homozygous deletion of CFHR3-1Δ (P(meta) = 3.2×10(-7), OR = 1.47) conferred a higher risk of SLE than heterozygous deletion (P(meta) = 3.5×10(-4), OR = 1.14). These results suggested that the CFHR3-1Δ deletion within the SLE-associated block, but not the previously described exonic SNPs of CFH, might contribute to the development of SLE in EA, AA, and AS, providing new insights into the role of complement regulators in the pathogenesis of SLE.


Assuntos
Antígenos de Neoplasias/genética , Biomarcadores Tumorais/genética , Fator H do Complemento/genética , Predisposição Genética para Doença , Lúpus Eritematoso Sistêmico/genética , Polimorfismo de Nucleotídeo Único , Afro-Americanos/genética , Alelos , Grupo com Ancestrais do Continente Asiático/genética , Estudos de Casos e Controles , Cromossomos Humanos Par 1/genética , Grupo com Ancestrais do Continente Europeu/genética , Deleção de Genes , Frequência do Gene , Genótipo , Hispano-Americanos/genética , Humanos , Íntrons , Lúpus Eritematoso Sistêmico/etnologia
19.
Arthritis Rheum ; 63(9): 2755-63, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21590681

RESUMO

OBJECTIVE: T cells from patients with systemic lupus erythematosus (SLE) express increased amounts of PP2Ac, which contributes to decreased production of interleukin-2 (IL-2). Because IL-2 is important in the regulation of several aspects of the immune response, it has been proposed that PP2Ac contributes to the expression of SLE. This study was designed to determine whether genetic variants of PPP2AC are linked to the expression of SLE and specific clinical manifestations and account for the increased expression of PP2Ac. METHODS: We conducted a trans-ethnic study of 8,695 SLE cases and 7,308 controls of 4 different ancestries. Eighteen single-nucleotide polymorphisms (SNPs) across PPP2CA were genotyped using an Illumina custom array. PPP2CA expression in SLE and control T cells was analyzed by real-time polymerase chain reaction. RESULTS: A 32-kb haplotype comprising multiple SNPs of PPP2CA showed significant association with SLE in Hispanic Americans, European Americans, and Asians, but not in African Americans. Conditional analyses revealed that SNP rs7704116 in intron 1 showed consistently strong association with SLE across Asian, European American, and Hispanic American populations (odds ratio 1.3 [95% confidence interval 1.14-1.31], meta-analysis P=3.8×10(-7)). In European Americans, the largest ethnic data set studied, the risk A allele of rs7704116 was associated with the presence of renal disease, anti-double-stranded DNA, and anti-RNP antibodies. PPP2CA expression was ∼2-fold higher in SLE patients carrying the rs7704116 AG genotype than those carrying the GG genotype (P=0.007). CONCLUSION: Our data provide the first evidence of an association between PPP2CA polymorphisms and elevated PP2Ac transcript levels in T cells, which implicates a new molecular pathway for SLE susceptibility in European Americans, Hispanic Americans, and Asians.


Assuntos
Predisposição Genética para Doença , Lúpus Eritematoso Sistêmico/genética , Polimorfismo Genético , Proteína Fosfatase 2/genética , Adolescente , Adulto , Alelos , Grupo com Ancestrais do Continente Asiático , Grupo com Ancestrais do Continente Europeu , Feminino , Estudos de Associação Genética , Genótipo , Haplótipos , Hispano-Americanos , Humanos , Interleucina-2/genética , Interleucina-2/metabolismo , Lúpus Eritematoso Sistêmico/imunologia , Masculino , Pessoa de Meia-Idade , Linfócitos T/metabolismo
20.
Arthritis Rheum ; 62(11): 3265-76, 2010 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-20722033

RESUMO

OBJECTIVE: To test for associations between non-major histocompatibility complex susceptibility loci previously reported in autoimmune diseases and juvenile idiopathic arthritis (JIA). METHODS: Published autoimmune disease genome-wide association studies were reviewed, and 519 single-nucleotide polymorphisms (SNPs) were selected for association testing. The initial cohort included 809 JIA cases and 3,535 controls of non-Hispanic, European ancestry. Of the SNPs, 257 were successfully genotyped, while 168 were imputed with quality. Based on findings in the initial cohort, replication was sought for 21 SNPs in a second cohort of 1,015 JIA cases and 1,569 controls collected in the US and Germany. For the initial cohort, tests for association were adjusted for potential confounding effects of population structure by including principal components derived from a genome-wide association study as covariates in logistic regression models. Odds ratios (ORs) and 95% confidence intervals were calculated. RESULTS: Testing for association of previously reported autoimmune disease genetic associations in the initial cohort suggested associations with JIA in 13 distinct loci. Of these, 7 were validated in the replication cohort. Meta-analysis results for the replicating loci included PTPN22 (rs6679677 [OR 1.58, P = 1.98 × 10(-12) ], rs2476601 [OR 1.64, P = 1.90 × 10(-13) ], and rs2488457 [OR 1.32, P = 6.74 × 10(-8) ]), PTPN2 (rs1893217 [OR = 1.33, P = 1.60 × 10(-9) ] and rs7234029 [OR 1.35, P = 1.86 × 10(-10) ]), ADAD1-IL2-IL21 (rs17388568 [OR 1.24, P = 1.13 × 10(-6) ] and rs13143866 [OR 0.83, P = 1.95 × 10(-4) ]), STAT4 (rs3821236 [OR = 1.27, P = 2.36 × 10(-6) ] and rs7574865 [OR = 1.31, P = 2.21 × 10(-6) ]), C12orf30 (rs17696736 [OR = 1.19, P = 2.59 × 10(-5) ]), COG6 (rs7993214 [OR = 0.76, P = 1.10 × 10(-5) ]), and ANGPT1 (rs1010824 [OR = 0.79, P = 2.91 × 10(-4) ]). These polymorphisms have been reported in diseases such as rheumatoid arthritis, type 1 diabetes mellitus, Crohn's disease, and multiple sclerosis. CONCLUSION: General susceptibility loci for autoimmunity are shared across diseases, including JIA, suggesting the potential for common therapeutic targets and mechanisms.


Assuntos
Proteínas Adaptadoras de Transporte Vesicular/genética , Angiopoietina-1/genética , Artrite Juvenil/genética , Proteína Tirosina Fosfatase não Receptora Tipo 2/genética , Alelos , Criança , Pré-Escolar , Feminino , Frequência do Gene , Estudos de Associação Genética , Predisposição Genética para Doença , Genótipo , Humanos , Masculino , Razão de Chances , Polimorfismo de Nucleotídeo Único
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