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From SNPedia

Geno Mag Summary
(A;A) 1 no increased risk of autoimmune thyroid disease
(A;G) 1.5 1.5x risk of autoimmune thyroiditis
(G;G) 2.3 2.3x risk of Hashimoto's thyroiditis, 1.47x risk of Graves' disease
ReferenceGRCh38 38.1/141
is asnp
is mentioned by
dbSNP (classic)rs231775
1000 genomesrs231775
GWAS Ctlgrs231775
Max Magnitude2.3
? (A;A) (A;G) (G;G) 28

Risk Rs231775(G;G) rs231775(T;T)
Alt Rs231775(G;G) rs231775(T;T)
Reference Rs231775(A;A)
Significance Other
Disease Hashimoto thyroiditis Thyroid-associated orbitopathy Systemic lupus erythematosus Diabetes mellitus Celiac disease 3 not specified
Variation info
Gene CTLA4
CLNDBN Hashimoto thyroiditis, susceptibility to Thyroid-associated orbitopathy, susceptibility to Systemic lupus erythematosus, susceptibility to Diabetes mellitus, insulin-dependent, susceptibility to Celiac disease 3 not specified
Reversed 0
HGVS NC_000002.11:g.204732714A>G
CLNSRC OMIM Allelic Variant UniProtKB (protein)
CLNACC RCV000018423.2, RCV000018424.2, RCV000018425.2, RCV000018426.2, RCV000018427.2, RCV000455037.1,


rs231775, also known as +49A>G (or CTLA-4 A49G), is a polymorphism of the CTLA4 gene. Polymorphisms are associated with several autoimmune diseases, especially autoimmune thyroiditis, as well as several other disorders.

[PMID 27638540OA-icon.png] A 2017 study titled "CD28/CTLA-4/ICOS haplotypes confers susceptibility to Graves’ disease and modulates clinical phenotype of disease" found that rs5742909 CC and rs231775 G allele "were associated with the family burden of GD" (Graves' disease, a form of Autoimmune thyroiditis). The G allele at rs231775 did not affect risk for Graves' Orbitopathy (GO), but favored severe disease outcome for GO. The presence of the A allele "was significantly associated with sporadic GD."

[PMID 27111218OA-icon.png] A 2016 study titled "Association of Cytotoxic T-Lymphocyte-Associated Protein 4 (CTLA4) Gene Polymorphisms with Autoimmune Thyroid Disease in Children and Adults: Case-Control Study" found that in a Han Chinese population, rs231775 "Genotype G/G conferred a risk of 1.55 (95% CI, 1.20–2.02; Pc = 0.002) for GD (Graves' disease) in adults and of 1.56 (95% CI, 1.19–2.05; Pc = 0.002) in children. Allele G was significantly associated with GD (Graves' disease) in adults (OR, 1.50; 95% CI, 1.21–1.84; Pc < 0.001) and in children (OR, 1.42; 95% CI, 1.15–1.77; Pc = 0.002)."

[PMID 26963610OA-icon.png] A 2016 study titled "Association of Cytotoxic T-Lymphocyte Antigen 4 (CTLA4) and Thyroglobulin (TG) Genetic Variants with Autoimmune Hypothyroidism" sampled 84 hypothyroidism patients and 62 controls from Gujarat, India. Researchers found that CTLA4 Exon1 (+49A/G) rs231775 polymorphisms increased the odds of autoimmune hypothyroidism in their sample: Odds ratios were

  • for AA, 1.0 (Genotypes were similar between patients and controls)
  • for AG, 5.333 (95%CI 2.043 to 13.92, p=0.0004) compared to AA
  • for GG, 5.778 (95%CI 1.829 to 18.25, p=0.0004) compared to AA

They also discovered that polymorphisms of rs231775 were associated with significantly decreased mRNA expression of both full length (flCTLA4) and soluble (sCTLA4) transcripts.

  • AA genotypes were similar between patients and controls.
  • AG decreased expression of both significantly (by p = 0.0141 for flCTLA4, and by p = 0.0358 for sCTLA4) in patients compared to controls
  • GG decreased expression levels slightly (by p = 0.0007 for flCTLA4, and by p = 0.0102 for sCTLA4) in patients compared to controls

They also found significant differences in patients vs. controls when analyzing the TG exon 33 SNP rs2076740.

[PMID 25005490OA-icon.png] A 2014 study titled "The association of PTPN22 rs2476601 polymorphism and CTLA-4 rs231775 polymorphism with LADA risks: a systematic review and meta-analysis" examined Latent Autoimmune Diabetes in Adults (LADA) and found that "The minor T allele at rs2476601 and the minor G at rs231775 carried estimated relative risks (odds ratio) of 1.52 (95 % CI 1.29–1.79) and 1.39 (95 % CI 1.11–1.74), respectively. These alleles contributed to an absolute lowering of the risk of all LADA (latent autoimmune diabetes in adults) by 4.88 and 14.93 % when individuals do not carry these alleles." Researchers stated that "LADA accounts for 2–12 % of all cases of diabetes" but "The progression to insulin dependence in LADA patients is believed more rapidly than classic type 2 diabetes patients" and "8–10 % of patients diagnosed with T2D are in fact misdiagnosed LADA."

[PMID 26823853OA-icon.png] A 2015 study titled "Association between CTLA-4 rs231775 polymorphism and hepatocellular carcinoma susceptibility" revealed that "The frequencies of genotype AA and allele A in CTLA-4 rs231775 polymorphism were significantly higher in cases" of liver cancer than the control group (AA vs. GG: OR=2.81, P=0.043; A vs. G: OR=1.63, P=0.022). Meanwhile, the genetic expression level of CTLA-4 was remarkably higher in cases compared with the controls. The association analysis indicated that AA genotype carriers exhibited highest level of CTLA-4 (P<0.01)."

[PMID 26221222OA-icon.png] A 2015 study titled "Associations between CTLA-4 +49 A/G (rs231775) polymorphism and cancer risk: a meta-analysis based on 52 case-control studies" stated "This meta-analysis suggests that the CTLA-4 +49 A/G polymorphism may be a protective factor for cancer." The minor G allele decreased cancer risk overall and for a large number of cancer types, "especially for breast cancer, lung cancer, and other cancers, epithelial tumor, respiratory system cancer, reproductive and breast cancer, malignant bone tumor," "but not digestive system cancer, hematopoietic malignancy and skin cancer." Most of the decreased cancer risk was in Asian populations. Table 3 data demonstrated "association between the risk of cancer and the CTLA-4 +49 A/G polymorphism (GG+AG vs. AA)." Although most of the Asian data showed "decreased risk," a few studies showed extreme increased risk, and these data skewed the average OD. On average, the data showed 0.85 OD of decreased cancer risk overall (0.98 for Caucasians and 0.76 for Asians).

[PMID 18776148OA-icon.png] Joint genetic susceptibility to type 1 diabetes and autoimmune thyroiditis: from epidemiology to mechanisms. In this 2008 article, researchers reported that "One of the best demonstrations of the power of subset analysis is the CTLA-4 gene in T1D. Although CTLA-4 showed very weak association with T1D, when analyzed in the subset of patients with both T1D and AITD, the genetic effect of CTLA-4 was significantly stronger." Note: rs231775 is one SNP within the CTLA-4 gene.

[PMID 22718509] Association between CTLA-4 exon-1 +49A/G polymorphism and systemic lupus erythematosus: an updated analysis. Published 2012. From abstract: "The combined results showed that there were significant differences in genotype distribution between SLE cases and control on the basis of all studies, GG versus AA (OR = 1.53, 95 % CI: 1.12-2.10), GG versus GA/AA (OR = 1.30, 95 % CI: 1.04-1.64), GG versus GA (OR = 1.27, 95 % CI: 1.03-1.55). When stratifying for the race, the phenomenon was found that SLE cases had a significantly higher frequency of GG/GA versus AA (OR = 1.58, 95 % CI: 1.23-2.03), GG versus AA (OR = 1.89, 95 % CI: 1.23-2.91), GG versus GA/AA(OR = 1.39, 95 % CI: 1.03-1.89), GA versus AA(OR = 1.38, 95 % CI: 1.06-1.80) and G versus A(OR = 1.34, 95 % CI: 1.07-1.67) than control in Asians." (Abstract)

[PMID 18059468] rs231775 (CTLA4_+49_G/A P=0.0219) and rs733618 (CTLA4_-1722_T/C P=0.0096) susceptibility to Graves' disease

[PMID 18076363] associated with the development of placental abruption and preeclampsia, with women having the G allele being at risk

[PMID 19490216] rs231775 was not associated with type-1 diabetes in a study of 207 Portuguese patients.

[PMID 19438904] Clinical associations of the genetic variants of CTLA-4, Tg, TSHR, PTPN22, PTPN12 and FCRL3 in patients with Graves' disease

[PMID 19175525OA-icon.png]In a meta-analysis of CTLA4 gene SNPs, rs231775 was most associated with vitiligo; however, the association seems to hold only in the subgroup of patients with other autoimmune diseases.

[PMID 19778566] +49G>A polymorphism in the CTLA-4 gene increases susceptibility to HBV-related HCC in male Chinese population

[PMID 19780033] Association of a functional polymorphism of PTPN22 encoding a lymphoid protein phosphatase in bilateral Meniere's disease

[PMID 19386687] CTLA4 gene polymorphisms are associated with chronic bronchitis

[PMID 20538028] CTLA-4 gene polymorphism +49 A/G is contributed to genetic susceptibility to two infection related cancers: hepatocellular carcinoma and cervical cancer

[PMID 20940051] Polymorphisms of the CTLA4 gene and kidney transplant rejection in Korean patients

[PMID 21040781] CTLA-4 confers a risk of recurrent schizophrenia, major depressive disorder and bipolar disorder in the Chinese Han population

[PMID 21513760] Association of CTLA4 gene polymorphisms with lymphatic filariasis in an East Malaysian population

[PMID 22011251] Cytotoxic T-Lymphocyte Antigen-4 +49G/A Polymorphism and Susceptibility to Pancreatic Cancer

[PMID 15452244OA-icon.png] Cytotoxic T-lymphocyte antigen 4 gene and recovery from hepatitis B virus infection.

[PMID 15726497OA-icon.png] Gene-environment interaction effects on the development of immune responses in the 1st year of life.

[PMID 16380915OA-icon.png] Replication of putative candidate-gene associations with rheumatoid arthritis in >4,000 samples from North America and Sweden: association of susceptibility with PTPN22, CTLA4, and PADI4.

[PMID 16449530OA-icon.png] Cytokine polymorphisms in the Th1/Th2 pathway and susceptibility to non-Hodgkin lymphoma.

[PMID 16872485OA-icon.png] Three allele combinations associated with multiple sclerosis.

[PMID 17327408OA-icon.png] Prognostic significance of host immune gene polymorphisms in follicular lymphoma survival.

[PMID 17683561OA-icon.png] The TCF7L2 locus and type 1 diabetes.

[PMID 17825114OA-icon.png] Association of CTLA-4 gene polymorphisms with sporadic breast cancer in Chinese Han population.

[PMID 18200060] PTPN22 is genetically associated with risk of generalized vitiligo, but CTLA4 is not.

[PMID 18456185OA-icon.png] Genetics and genomics of primary biliary cirrhosis.

[PMID 18528295OA-icon.png] Influence of cytotoxic T lymphocyte-associated antigen 4 (CTLA4) common polymorphisms on outcome in treatment of melanoma patients with CTLA-4 blockade.

[PMID 18556337OA-icon.png] Impact of diabetes susceptibility loci on progression from pre-diabetes to diabetes in at-risk individuals of the diabetes prevention trial-type 1 (DPT-1).

[PMID 18576317OA-icon.png] Lack of association of functional CTLA4 polymorphisms with juvenile idiopathic arthritis.

[PMID 18633131OA-icon.png] Host immune gene polymorphisms in combination with clinical and demographic factors predict late survival in diffuse large B-cell lymphoma patients in the pre-rituximab era.

[PMID 18687755OA-icon.png] Genetic variants in T helper cell type 1, 2 and 3 pathways and gastric cancer risk in a Polish population.

[PMID 18773895OA-icon.png] The genetic basis of primary biliary cirrhosis: premises, not promises.

[PMID 18778710OA-icon.png] Primary biliary cirrhosis is associated with a genetic variant in the 3' flanking region of the CTLA4 gene.

[PMID 18805939OA-icon.png] Functional genetic polymorphisms and female reproductive disorders: part II--endometriosis.

[PMID 19014504OA-icon.png] Lack of association between sCTLA-4 levels in human plasma and common CTLA-4 polymorphisms.

[PMID 19066394OA-icon.png] Organochlorine exposure, immune gene variation, and risk of non-Hodgkin lymphoma.

[PMID 19131662OA-icon.png] A meta-analysis of candidate gene polymorphisms and ischemic stroke in 6 study populations: association of lymphotoxin-alpha in nonhypertensive patients.

[PMID 19141582OA-icon.png] Autoimmune thyroiditis and diabetes: dissecting the joint genetic susceptibility in a large cohort of multiplex families.

[PMID 19147066OA-icon.png] Genomic and proteomic analysis of allogeneic hematopoietic cell transplant outcome. Seeking greater understanding the pathogenesis of GVHD and mortality.

[PMID 19173720OA-icon.png] Low frequency of CD4+CD25+ Treg in SLE patients: a heritable trait associated with CTLA4 and TGFbeta gene variants.

[PMID 19180256OA-icon.png] Genotype analysis of polymorphisms in autoimmune susceptibility genes, CTLA-4 and PTPN22, in an acute anterior uveitis cohort.

[PMID 19188433OA-icon.png] Do non-HLA genes influence development of persistent islet autoimmunity and type 1 diabetes in children with high-risk HLA-DR,DQ genotypes?

[PMID 19263529OA-icon.png] Genetic risk factors in recurrent venous thromboembolism: A multilocus, population-based, prospective approach.

[PMID 19300490OA-icon.png] An African ancestry-specific allele of CTLA4 confers protection against rheumatoid arthritis in African Americans.

[PMID 19330901OA-icon.png] Association of 77 polymorphisms in 52 candidate genes with blood pressure progression and incident hypertension: the Women's Genome Health Study.

[PMID 19379518OA-icon.png] Development of a fingerprinting panel using medically relevant polymorphisms.

[PMID 19559392OA-icon.png] A candidate gene association study of 77 polymorphisms in migraine.

[PMID 19609446OA-icon.png] CTLA4 autoimmunity-associated genotype contributes to severe pulmonary tuberculosis in an African population.

[PMID 19622768OA-icon.png] CTLA4 variants, UV-induced tolerance, and risk of non-melanoma skin cancer.

[PMID 19672595OA-icon.png] Polymorphisms in the CD28/CTLA4/ICOS genes: role in malignant melanoma susceptibility and prognosis?

[PMID 19740340OA-icon.png] The CTLA-4 gene polymorphisms are associated with CTLA-4 protein expression levels in multiple sclerosis patients and with susceptibility to disease.

[PMID 19956097OA-icon.png] Remapping the type I diabetes association of the CTLA4 locus.

[PMID 19956109OA-icon.png] The Type I Diabetes Genetics Consortium 'Rapid Response' family-based candidate gene study: strategy, genes selection, and main outcome.

[PMID 20352109OA-icon.png] Association of the CTLA4 gene with Graves' disease in the Chinese Han population.

[PMID 20444755OA-icon.png] Investigation of rheumatoid arthritis susceptibility genes identifies association of AFF3 and CD226 variants with response to anti-tumour necrosis factor treatment.

[PMID 20537165OA-icon.png] The CTLA4 variants may interact with the IL23R- and NOD2-conferred risk in development of Crohn's disease.

[PMID 20557968] Association analysis of cytotoxic T-lymphocyte antigen 4 gene polymorphisms with primary biliary cirrhosis in Japanese patients.

[PMID 20565774OA-icon.png] Population based allele frequencies of disease associated polymorphisms in the Personalized Medicine Research Project.

[PMID 20610662OA-icon.png] Association of single nucleotide polymorphisms in cytotoxic T-lymphocyte antigen 4 and susceptibility to autoimmune type 1 diabetes in Tunisians.

[PMID 20732370] CTLA4 and CD86 gene polymorphisms and susceptibility to chronic obstructive pulmonary disease.

[PMID 21085187OA-icon.png] Comprehensive association analysis of candidate genes for generalized vitiligo supports XBP1, FOXP3, and TSLP.

[PMID 21453059] Cytotoxic T-lymphocyte antigen-4 +49G/A polymorphism is associated with increased risk of osteosarcoma.

[PMID 21669243] CTLA-4, CD28, and ICOS gene polymorphism associations with non-small-cell lung cancer.

[PMID 21952918OA-icon.png] Evidence for gene-gene epistatic interactions among susceptibility loci for systemic lupus erythematosus.

[PMID 22076708] Validation of genetic sequence variants as prognostic factors in early-stage head and neck squamous cell cancer survival.

[PMID 22288822OA-icon.png] A pilot study on cytotoxic T lymphocyte-4 gene polymorphisms in urinary schistosomiasis.

[PMID 22376040] Gene-gene interactions between candidate gene polymorphisms are associated with total IgE levels in Korean children with asthma.

[PMID 22414241] Cytotoxic T-lymphocyte associated antigen-4 gene polymorphisms and primary biliary cirrhosis: A systematic review.

[PMID 22418270] Polymorphisms in cytotoxic T lymphocyte associated antigen-4 influence the rate of acute rejection after renal transplantation in 167 Chinese recipients.

[PMID 23018253] The impact of rs231775 (+49AG) CTLA4 gene polymorphism on transplanted kidney function

[PMID 23432218] Association between cytotoxic T-lymphocyte antigen 4 gene polymorphisms and primary biliary cirrhosis in Chinese population: data from a multicenter study

[PMID 23480667] Cytotoxic T-Lymphocyte Antigen-4 Genetic Variants and Risk of Ewing's Sarcoma

[PMID 23567921] Cytotoxic T-lymphocyte antigen 4 (CTLA4) +49AG and CT60 gene polymorphisms in Alopecia Areata: a case-control association study in the Italian population

[PMID 23597029OA-icon.png] The associations between the polymorphisms in the CTLA-4 gene and the risk of Graves' disease in the Chinese population

[PMID 23661460] CTLA-4 and CD86 genetic variants and haplotypes in patients with rheumatoid arthritis in southeastern China

[PMID 23703660] The -319C/+49G/CT60G Haplotype of CTLA-4 Gene Confers Susceptibility to Rheumatoid Arthritis in Mexican Population

[PMID 23830732] CTLA-4 gene polymorphism at position +49 A>G in exon 1: a risk factor for cervical cancer in Indian women

[PMID 23944755] The impact of CTLA4 and PTPN22 genes polymorphisms on long-term renal allograft function and transplant outcomes

[PMID 23961418OA-icon.png] Association of the HLA locus and TNF with type I autoimmune hepatitis susceptibility in New Zealand Caucasians

[PMID 24015180OA-icon.png] CTLA4 Gene Polymorphisms Influence the Incidence of Infection after Renal Transplantation in Chinese Recipients

[PMID 24270470] Influence of cytotoxic T lymphocyte-associated antigen 4 polymorphisms on the outcomes of hepatitis B virus infection

[PMID 24298899] Investigation of CTLA-4 and CD86 gene polymorphisms in a group of Iranian patients with brucellosis infection

[PMID 24313821] Association of CTLA-4 Gene Polymorphism with End-Stage Renal Disease and Renal Allograft Outcome

[PMID 24385694OA-icon.png] Effect of cytotoxic T-lymphocyte antigen-4, TNF-alpha polymorphisms on osteosarcoma: evidences from a meta-analysis

[PMID 22328738OA-icon.png] Comprehensive assessment of rheumatoid arthritis susceptibility loci in a large psoriatic arthritis cohort.

[PMID 22905924] Cytotoxic T-lymphocyte antigen-4 polymorphisms and susceptibility to Ewing's sarcoma.

[PMID 23010350] Lack of association between CTLA-4 +49A/G and -318C/T polymorphisms and Behcet's disease risk: a meta-analysis.

[PMID 23133602OA-icon.png] Pharmacogenetics of efficacy and safety of HCV treatment in HCV-HIV coinfected patients: significant associations with IL28B and SOCS3 gene variants.

[PMID 23261825] Association between cytotoxic T lymphocyte antigen-4 polymorphism and type 1 diabetes: a meta-analysis.

[PMID 25005490OA-icon.png] The association of PTPN22 rs2476601 polymorphism and CTLA-4 rs231775 polymorphism with LADA risks: a systematic review and meta-analysis

[PMID 25785040OA-icon.png] Association between CTLA-4 rs231775 polymorphism and risk of colorectal cancer: a meta analysis

[PMID 25940108OA-icon.png] A CT60G>A polymorphism in the CTLA-4 gene of the recipient may confer susceptibility to acute graft versus host disease after allogeneic hematopoietic stem cell transplantation

[PMID 26079279] HCV F protein amplifies the predictions of IL-28B and CTLA-4 polymorphisms about the susceptibility and outcomes of HCV infection in Southeast China

[PMID 26403483] CTLA-4 and CD28 genes' polymorphisms and renal cell carcinoma susceptibility in the Polish population - a prospective study

[PMID 26546236] CTLA-4+49 A/G polymorphism and antiglutamic acid decarboxylase antibody-associated encephalopathy in Taiwanese children

[PMID 26582004] Association of CTLA4 exon-1 polymorphism with the tumor necrosis factor-α in the risk of systemic lupus erythematosus among South Indians

[PMID 28052683] Cytotoxic T Lymphocyte-Associated Antigen 4 rs231775 polymorphism and Osteosarcoma: an updated systematic review and meta-analysis.

[PMID 28384040] CTLA-4 +49 G/A Polymorphism Confers Autoimmune Disease Risk: An Updated Meta-Analysis.

[PMID 29130827] Association of Single-Nucleotide Polymorphisms in Immune-Related Genes with Development of Dengue Hemorrhagic Fever in a Mexican Population.

[PMID 29264740] CTLA-4 polymorphisms are associated with treatment outcomes of patients with multiple myeloma receiving bortezomib-based regimens.

[PMID 29409002] PTPN22 and CTLA-4 Polymorphisms are Associated with Polyglandular Autoimmunity.

[PMID 29476189OA-icon.png] The synergic effects of CTLA-4/Foxp3-related genotypes and chromosomal aberrations on the risk of recurrent spontaneous abortion among a Chinese Han population.

[PMID 29719630OA-icon.png] Genetic susceptibility to bone and soft tissue sarcomas: a field synopsis and meta-analysis.

[PMID 29794444] Association of Five Snps in Cytotoxic T-Lymphocyte Antigen 4 and Cancer Susceptibility: Evidence from 67 Studies.

[PMID 29973665OA-icon.png] CTLA-4 +49 G/A, a functional T1D risk SNP, affects CTLA-4 level in Treg subsets and IA-2A positivity, but not beta-cell function.

[PMID 30223781OA-icon.png] Correlation between CTLA-4 and CD40 gene polymorphisms and their interaction in graves' disease in a Chinese Han population.

[PMID 30310101OA-icon.png] The CTLA-4 rs231775 GG genotype is associated with favorable 90-day survival in Caucasian patients with sepsis.

[PMID 30465728] CTLA-4 polymorphism rs231775: influence on relapse and survival after allogeneic hematopoietic stem cell transplantation in childhood.

[PMID 31883177] Association of cytotoxic T-lymphocyte associated protein 4 gene polymorphisms with the risk and prognosis of oesophageal cancer in a high-incidence region from northern China.

[PMID 32731768] Association of Rs231775 Genetic Variant of Cytotoxic T-lymphocyte Associated Protein 4 with Alopecia Areata Disease in Males: A Case-Control Study.

[PMID 33226370OA-icon.png] A systematic review and network meta-analysis of single nucleotide polymorphisms associated with pancreatic cancer risk.