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Salauddin A, Chakma K, Hasan MM, Akter F, Chowdhury NA, Chowdhury SR, Mannan A. Association between TCF7L2 polymorphism and type 2 diabetes mellitus susceptibility: a case-control study among the Bangladeshi population. Mol Biol Rep 2023; 50:609-619. [PMID: 36369331 DOI: 10.1007/s11033-022-08081-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2022] [Accepted: 11/01/2022] [Indexed: 11/13/2022]
Abstract
BACKGROUND Diabetes is a severe health burden for Bangladesh. Genetic polymorphism has been reported to be one of the major risk factors for diabetes in various studies. TCF7L2 (transcription factor 7 like 2) transcripts in the human β-cell have effects on β-cell survival, function, and Wnt signaling activation. This study aimed to evaluate the frequency and association of various polymorphisms namely TCF7L2 rs12255372 and rs7903146 among Bangladeshi patients with T2DM (Type 2 Diabetes Mellitus). METHODS This case-control study included 300 patients with T2DM and 234 healthy individuals from two health facilities in the Chattogram Division of Bangladesh. Anthropometric measurements were assessed using a self-reported, structured, eight-item questionnaire. The polymorphisms were identified by PCR-RFLP and sequencing method. RESULTS A strong association of T2DM with polymorphisms was observed, including rs12255372 (p = 0.0004) and rs7903146 (p = 0.005). It was observed that the risk genotype at rs12255372 was associated with age (p = 0.009), a family history of diabetes (p < 0.0001), and HbA1C (p < 0.0001). Furthermore, it was found that rs12255372 was substantially associated with hypertension (p = 0.03), eye problems (p = 0.01), and neurological abnormalities (p = 0.02). CONCLUSION This study postulates that TCF7L2 genetic polymorphism is associated with the risk of T2DM among the studied Bangladeshi population. The findings should be replicated through more studies with a large number of samples and in different populations.
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Affiliation(s)
- Asma Salauddin
- Department of Genetic Engineering & Biotechnology, Faculty of Biological Sciences, University of Chittagong, Chattogram, 4331, Bangladesh.,Disease Biology and Molecular Epidemiology Research Group, Chattogram, Bangladesh
| | - Kallyan Chakma
- Department of Genetic Engineering & Biotechnology, Faculty of Biological Sciences, University of Chittagong, Chattogram, 4331, Bangladesh.,Disease Biology and Molecular Epidemiology Research Group, Chattogram, Bangladesh
| | - Md Mahbub Hasan
- Department of Genetic Engineering & Biotechnology, Faculty of Biological Sciences, University of Chittagong, Chattogram, 4331, Bangladesh.,Disease Biology and Molecular Epidemiology Research Group, Chattogram, Bangladesh
| | - Farhana Akter
- Department of Endocrinology, Chittagong Medical College, Chattogram, 4203, Bangladesh.,Disease Biology and Molecular Epidemiology Research Group, Chattogram, Bangladesh
| | | | | | - Adnan Mannan
- Department of Genetic Engineering & Biotechnology, Faculty of Biological Sciences, University of Chittagong, Chattogram, 4331, Bangladesh. .,Disease Biology and Molecular Epidemiology Research Group, Chattogram, Bangladesh.
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2
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Ergür E, Ergür E, Alnek K, Metsküla K, Peet A, Lubi M, Heilman K, Uibo R. Clinical signs of type 1 diabetes are associated with type 2 diabetes marker transcription factor 7-like 2 polymorphism. J Diabetes Investig 2022; 14:221-229. [PMID: 36300877 PMCID: PMC9889689 DOI: 10.1111/jdi.13933] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Revised: 09/22/2022] [Accepted: 10/11/2022] [Indexed: 02/04/2023] Open
Abstract
AIMS/INTRODUCTION We aimed to assess the distribution of transcription factor 7-like 2 gene TCF7L2 (rs7903146) polymorphism and to find possible associations between TCF7L2 and the characteristics of type 1 diabetes. MATERIALS AND METHODS We studied 190 newly diagnosed type 1 diabetes patients (median age 12.7 years, range 2.0-72.5) and 246 controls (median age 23.8 years, range 1.4-81.5) for TCF7L2 single nucleotide polymorphism. We determined anti-islet autoantibodies, random C-peptide levels, diabetes associated HLA DR/DQ haplotypes and genotypes in all patients. RESULTS There were no differences in the distribution of TCF7L2 single nucleotide polymorphism between patients and controls. However, patients with in type 1 diabetes, after adjusting for age and sex, subjects carrying C allele were at risk for a C-peptide level lower than 0.5 nmol/L (OR 5.65 [95% CI: 1.14-27.92]) and for zinc transporter 8 autoantibody positivity (5.22 [1.34-20.24]). Participants without T allele were associated with a higher level of islet antigen-2 autoantibodies (3.51 [1.49-8.27]) and zinc transporter 8 autoantibodies (2.39 [1.14-4.99]). CONCLUSIONS The connection of TCF7L2 polymorphism with zinc transporter 8 and islet antigen-2 autoantibodies and C-peptide levels in patients supports the viewpoint that TCF7L2 is associated with the clinical signs and autoimmune characteristics of type 1 diabetes. The mechanisms of the interaction between the TCF7L2 risk genotype and anti-islet autoantibodies need to be studied further.
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Affiliation(s)
- Efe Ergür
- Department of Immunology, Institute of Bio‐ and Translational MedicineUniversity of TartuTartuEstonia
| | - Ege Ergür
- Department of Immunology, Institute of Bio‐ and Translational MedicineUniversity of TartuTartuEstonia
| | - Kristi Alnek
- Department of Immunology, Institute of Bio‐ and Translational MedicineUniversity of TartuTartuEstonia
| | - Kaja Metsküla
- Department of Immunology, Institute of Bio‐ and Translational MedicineUniversity of TartuTartuEstonia
| | - Aleksandr Peet
- Department of Pediatrics, Institute of Clinical MedicineUniversity of TartuTartuEstonia,Children's Clinic of Tartu University HospitalTartuEstonia
| | - Maire Lubi
- Department of Internal Medicine, Institute of Clinical MedicineUniversity of TartuTartuEstonia,Internal Medicine Clinic of Tartu University HospitalTartuEstonia
| | | | - Raivo Uibo
- Department of Immunology, Institute of Bio‐ and Translational MedicineUniversity of TartuTartuEstonia
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3
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Vilarrasa N, San Jose P, Rubio MÁ, Lecube A. Obesity in Patients with Type 1 Diabetes: Links, Risks and Management Challenges. Diabetes Metab Syndr Obes 2021; 14:2807-2827. [PMID: 34188505 PMCID: PMC8232956 DOI: 10.2147/dmso.s223618] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Accepted: 05/19/2021] [Indexed: 12/15/2022] Open
Abstract
Obesity affects large numbers of patients with type 1 diabetes (T1D) across their lifetime, with rates ranging between 2.8% and 37.1%. Patients with T1D and obesity are characterized by the presence of insulin resistance, of high insulin requirements, have a greater cardiometabolic risk and an enhanced risk of developing chronic complications when compared to normal-weight persons with T1D. Dual treatment of obesity and T1D is challenging and no specific guidelines for improving outcomes of both glycemic control and weight management have been established for this population. Nevertheless, although evidence is scarce, a comprehensive approach based on a balanced hypocaloric diet, physical activity and cognitive behavioral therapy by a multidisciplinary team, expert in both obesity and diabetes, remains as the best clinical practice. However, weight loss responses with lifestyle changes alone are limited, so in the "roadmap" of the treatment of obesity in T1D, it will be helpful to include anti-obesity pharmacotherapy despite at present there is a lack of evidence since T1D patients have been excluded from anti-obesity drug clinical trials. In case of severe obesity, bariatric surgery has proven to be of benefit in obtaining a substantial and long-term weight loss and reduction in cardiovascular risk. The near future looks promising with the development of new and more effective anti-obesity treatments and strategies to improve insulin resistance and oxidative stress. Advances in precision medicine may help individualize and optimize the medical management and care of these patients. This review, by gathering current evidence, highlights the need of solid knowledge in all facets of the treatment of patients with obesity and T1D that can only be obtained through high quality well-designed studies.
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Affiliation(s)
- Nuria Vilarrasa
- Department of Endocrinology and Nutrition, Hospital Universitario de Bellvitge-IDIBELL, Barcelona, Spain
- CIBERDEM-CIBER de Diabetes y Enfermedades Metabólicas Asociadas, Instituto de Salud Carlos III, Madrid, Spain
- Correspondence: Nuria Vilarrasa Hospital Universitario de Bellvitge-IDIBELL, C/Feixa Llarga s/n, 08907 L´Hospitalet de Llobregat, Barcelona, SpainTel +34 93-5338511Fax +34 933375248 Email
| | - Patricia San Jose
- Department of Endocrinology and Nutrition, Hospital Universitario de Bellvitge-IDIBELL, Barcelona, Spain
| | - Miguel Ángel Rubio
- Department of Endocrinology & Nutrition, Hospital Clínico San Carlos, IDISSC, Madrid, 28040, Spain
| | - Albert Lecube
- CIBERDEM-CIBER de Diabetes y Enfermedades Metabólicas Asociadas, Instituto de Salud Carlos III, Madrid, Spain
- Endocrinology and Nutrition Department, Hospital Universitari Arnau de Vilanova, Lleida, 25198, Spain
- Obesity, Diabetes and Metabolism (ODIM) Research Group, Institut de Recerca Biomèdica de Lleida (IRBLleida), University of Lleida, Lleida, Spain
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4
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Abstract
PURPOSE OF REVIEW Diabetes is a spectrum of clinical manifestations, including latent autoimmune diabetes in adults (LADA). However, it has been questioned whether LADA exists or simply is a group of misclassified type 1 diabetes (T1D) and type 2 diabetes (T2D) patients. This review will provide an updated overview of the genetics of LADA, highlight what genetics tell us about LADA as a diabetes subtype, and point to future directions in the study of LADA. RECENT FINDINGS Recent studies have verified the genetic overlap between LADA and both T1D and T2D and have contributed identification of a novel LADA-specific locus, namely, PFKFB3, and subtype-specific signatures in the HLA region. Genetic risk scores comprising T1D-risk variants have been shown to be a promising tool for discriminating diabetes subtypes and identifying patients rapidly progressing to insulin dependence. Genetic data support the existence of LADA, but further studies are needed to fully determine the place of LADA in the diabetes spectrum.
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Affiliation(s)
- Mette K Andersen
- The Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, DK-2200, Copenhagen N, Denmark.
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5
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Abstract
Over the past ∼15 years there has been great progress in our understanding of the genetics of both type 1 diabetes and type 2 diabetes. This has been driven principally by genome-wide association studies (GWAS) in increasingly larger sample sizes, where many distinct loci have now been reported for both traits. One of the loci that dominates these studies is the TCF7L2 locus for type 2 diabetes. This genetic signal has been leveraged to explore multiple aspects of disease risk, including developments in genetic risk scores, genetic commonalities with cancer, and for gaining insights into diabetes-related molecular pathways. Furthermore, the TCF7L2 locus has aided in providing insights into the genetics of both latent autoimmune diabetes in adults and various presentations of type 1 diabetes. This review outlines the knowledge gained to date and highlights how work with this locus leads the way in guiding how many other genetic loci could be similarly used to gain insights into the pathogenesis of diabetes.
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Affiliation(s)
- Struan F A Grant
- Divisions of Human Genetics and Endocrinology, Children's Hospital of Philadelphia, Philadelphia, PA
- Center for Spatial and Functional Genomics, Children's Hospital of Philadelphia, Philadelphia, PA
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
- Institute for Diabetes, Obesity and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
- Department of Pediatrics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
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6
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Abstract
Diabetes is a multifactorial disease, caused by a complex interplay between environmental and genetic risk factors. Genetic determinants of particularly Type 1 Diabetes (T1D) and Type 2 Diabetes (T2D) have been studied extensively, whereas well-powered studies of Latent Autoimmune Diabetes in Adults (LADA) are lacking. So far available studies support a clear genetic overlap between LADA and T1D, however, with smaller effect sizes of the T1D-risk variants in LADA as compared to T1D. A genetic overlap between LADA and T2D is less clear. However, recent studies, including large numbers of LADA patients, provide different lines of evidence to support a genetic overlap between T2D and LADA. The genetic predisposition to LADA is yet to be explored in a study design, like a genome- wide association study, which allows for analyses of the genetic predisposition independently of prior hypothesis about potential candidate genes. This type of study may facilitate the discovery of risk variants associated with LADA independently of T1D and T2D, and is central in order to determine if LADA should be considered as an independent diabetic subtype. Extended knowledge about the genetic predisposition to LADA may also facilitate stratification of the heterogeneous group of LADA patients, which may assist the choice of treatment. This mini-review summarizes current knowledge of the genetics of LADA, and discusses the perspectives for future studies.
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Affiliation(s)
- Mette Korre Andersen
- The Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Torben Hansen
- The Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
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7
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Abstract
Latent autoimmune diabetes in adults (LADA) is a heterogeneous disease characterized by a less intensive autoimmune process and a broad clinical phenotype compared to classical type 1 diabetes mellitus (T1DM), sharing features with both type 2 diabetes mellitus (T2DM) and T1DM. Since patients affected by LADA are initially insulin independent and recognizable only by testing for islet-cell autoantibodies, it could be difficult to identify LADA in clinical setting and a high misdiagnosis rate still remains among patients with T2DM. Ideally, islet-cell autoantibodies screening should be performed in subjects with newly diagnosed T2DM, ensuring a closer monitoring of those resulted positive and avoiding treatment of hyperglycaemia which might increase the rate of β-cells loss. Thus, since the autoimmune process in LADA seems to be slower than in classical T1DM, there is a wider window for new therapeutic interventions that may slow down β-cell failure. This review summarizes the current understanding of LADA, by evaluating data from most recent studies, the actual gaps in diagnosis and management. Finally, we critically highlight and discuss novel findings and future perspectives on the therapeutic approach in LADA.
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Affiliation(s)
- Silvia Pieralice
- Department of Endocrinology and Diabetes, University Campus Bio-Medico, Rome, Italy
| | - Paolo Pozzilli
- Department of Endocrinology and Diabetes, University Campus Bio-Medico, Rome, Italy
- Centre of Immunobiology, Blizard Institute, Barts and the London School of Medicine, Queen Mary University of London, London, UK.
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8
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Huda N, Hosen MI, Yasmin T, Sarkar PK, Hasan AKMM, Nabi AHMN. Genetic variation of the transcription factor GATA3, not STAT4, is associated with the risk of type 2 diabetes in the Bangladeshi population. PLoS One 2018; 13:e0198507. [PMID: 30044774 PMCID: PMC6059405 DOI: 10.1371/journal.pone.0198507] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2017] [Accepted: 05/21/2018] [Indexed: 12/20/2022] Open
Abstract
Type 2 diabetes mellitus is a multifactorial metabolic disorder caused by environmental factors and has a strong association with hereditary issues. These hereditary issues result in an imbalance in CD4+T cells and a decreased level of naïve CD4+T cells, which may be critical in the pathogenesis of type 2 diabetes. Transcription factors GATA3 and STAT4 mediate the cytokine-induced development of naïve T cells into Th1 or Th2 types. In the present study, genetic analyses of GATA3 SNP rs3824662 and STAT4 SNP rs10181656 were performed to investigate the association of allelic and genotypic variations with the risk of T2D in the Bangladeshi population. A total of 297 unrelated Bangladeshi patients with type 2 diabetes and 247 healthy individuals were included in the study. The allelic and genotypic frequencies of rs10181656 located in the STAT4 gene were not found to be associated with risk of type 2 diabetes. The GATA3 rs3824662 T allele and mutant TT genotype had a significant association with the risk of T2D [OR: 1.52 (1.15–2.02), X2 = 8.66, p = 0.003 and OR: 2.98 (1.36–6.55), X2 = 7.98, p = 0.04, respectively]. Thus, the present study postulates that the genetic variation of the transcription factor GATA3, not STAT4, is associated with the risk of type 2 diabetes in the Bangladeshi population.
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Affiliation(s)
- Nafiul Huda
- Laboratory of Population Genetics, Department of Biochemistry and Molecular Biology, University of Dhaka, Dhaka, Bangladesh
| | - Md. Ismail Hosen
- Laboratory of Population Genetics, Department of Biochemistry and Molecular Biology, University of Dhaka, Dhaka, Bangladesh
| | - Tahirah Yasmin
- Laboratory of Population Genetics, Department of Biochemistry and Molecular Biology, University of Dhaka, Dhaka, Bangladesh
| | | | - A. K. M. Mahbub Hasan
- Laboratory of Population Genetics, Department of Biochemistry and Molecular Biology, University of Dhaka, Dhaka, Bangladesh
| | - A. H. M. Nurun Nabi
- Laboratory of Population Genetics, Department of Biochemistry and Molecular Biology, University of Dhaka, Dhaka, Bangladesh
- * E-mail:
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9
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Redondo MJ, Geyer S, Steck AK, Sosenko J, Anderson M, Antinozzi P, Michels A, Wentworth J, Xu P, Pugliese A. TCF7L2 Genetic Variants Contribute to Phenotypic Heterogeneity of Type 1 Diabetes. Diabetes Care 2018; 41:311-317. [PMID: 29025879 PMCID: PMC5780048 DOI: 10.2337/dc17-0961] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/12/2017] [Accepted: 08/17/2017] [Indexed: 02/03/2023]
Abstract
OBJECTIVE The phenotypic diversity of type 1 diabetes suggests heterogeneous etiopathogenesis. We investigated the relationship of type 2 diabetes-associated transcription factor 7 like 2 (TCF7L2) single nucleotide polymorphisms (SNPs) with immunologic and metabolic characteristics at type 1 diabetes diagnosis. RESEARCH DESIGN AND METHODS We studied TrialNet participants with newly diagnosed autoimmune type 1 diabetes with available TCF7L2 rs4506565 and rs7901695 SNP data (n = 810; median age 13.6 years; range 3.3-58.6). We modeled the influence of carrying a TCF7L2 variant (i.e., having 1 or 2 minor alleles) on the number of islet autoantibodies and oral glucose tolerance test (OGTT)-stimulated C-peptide and glucose measures at diabetes diagnosis. All analyses were adjusted for known confounders. RESULTS The rs4506565 variant was a significant independent factor of expressing a single autoantibody, instead of multiple autoantibodies, at diagnosis (odds ratio [OR] 1.66 [95% CI 1.07, 2.57], P = 0.024). Interaction analysis demonstrated that this association was only significant in participants ≥12 years old (n = 504; OR 2.12 [1.29, 3.47], P = 0.003) but not younger ones (n = 306, P = 0.73). The rs4506565 variant was independently associated with higher C-peptide area under the curve (AUC) (P = 0.008) and lower mean glucose AUC (P = 0.0127). The results were similar for the rs7901695 SNP. CONCLUSIONS In this cohort of individuals with new-onset type 1 diabetes, type 2 diabetes-linked TCF7L2 variants were associated with single autoantibody (among those ≥12 years old), higher C-peptide AUC, and lower glucose AUC levels during an OGTT. Thus, carriers of the TCF7L2 variant had a milder immunologic and metabolic phenotype at type 1 diabetes diagnosis, which could be partly driven by type 2 diabetes-like pathogenic mechanisms.
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Affiliation(s)
- Maria J Redondo
- Baylor College of Medicine, Texas Children's Hospital, Houston, TX
| | | | - Andrea K Steck
- Barbara Davis Center for Childhood Diabetes, University of Colorado School of Medicine, Aurora, CO
| | | | - Mark Anderson
- University of California, San Francisco, San Francisco, CA
| | | | - Aaron Michels
- Barbara Davis Center for Childhood Diabetes, University of Colorado School of Medicine, Aurora, CO
| | - John Wentworth
- Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia
| | - Ping Xu
- University of South Florida, Tampa, FL
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10
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Redondo MJ, Grant SFA, Davis A, Greenbaum C. Dissecting heterogeneity in paediatric Type 1 diabetes: association of TCF7L2 rs7903146 TT and low-risk human leukocyte antigen (HLA) genotypes. Diabet Med 2017; 34:286-290. [PMID: 27027642 DOI: 10.1111/dme.13123] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 03/29/2016] [Indexed: 01/02/2023]
Abstract
AIMS To test the hypothesis that non-obese individuals with childhood-onset Type 1 diabetes and the rs7903146 TT genotype would be less likely to have high-risk human leukocyte antigen (HLA) genotypes and alleles. METHODS We studied a cohort of 105 non-obese participants in the T1D Exchange Biobank Residual Insulin Study who had childhood-onset Type 1 diabetes [mean (sd) age at onset and recruitment, respectively, 9.9 (4.15) and 14.4 (4.13) years; 84.8% non-Hispanic white]. We analysed islet autoantibodies (glutamic acid decarboxylase 65, islet cell autoantigen 512/islet antigen-2 and zinc transporter 8), non-fasting random C-peptide levels, HLA type and TCF7L2 single nucleotide polymorphism rs7903146 in this cohort. RESULTS None of the 13 individuals with the rs7903146 TT genotype carried the highest Type 1 diabetes risk HLA genotype, i.e. DRB1*03:01/DR4 (DRB1*0401, *04:05 or *04:02), compared with 29.4% (27/92) of those without it (P=0.023). The DRB1*03:01 allele was present in 15.4% (2/13) of individuals with the single nucleotide polymorphism, compared with 59.8% (55/92) of those without it (P=0.003). Analyses restricted to autoantibody-positive individuals (n=80) yielded similar results. The HLA DRB1*15:01 allele, which affords dominant protection against Type 1 diabetes, was found in one participant, who had multiple islet autoantibodies and carried the rs7903146 TT genotype. CONCLUSIONS These findings further support the hypothesis that TCF7L2 gene variation contributes to diabetogenesis in a subset of young people with Type 1 diabetes, opening possible new pathways for therapy and prevention.
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Affiliation(s)
- M J Redondo
- Department of Pediatrics, Section of Diabetes and Endocrinology, Texas Children's Hospital, Baylor College of Medicine, Houston, TX, USA
| | - S F A Grant
- Divisions of Human Genetics and Endocrinology, The Children's Hospital of Philadelphia, Philadelphia, PA, USA
- Department of Pediatrics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - A Davis
- Diabetes Clinical Research Program, Benaroya Research Institute, Seattle, WA, USA
| | - C Greenbaum
- Diabetes Clinical Research Program, Benaroya Research Institute, Seattle, WA, USA
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11
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Yadav SK, Rashmi, Tripathi KK, Singh R. Association of TCF7L2 gene variant with T2DM, T1DM and gestational diabetes in the population of Northeastern UP, India. Int J Diabetes Dev Ctries 2016. [DOI: 10.1007/s13410-016-0490-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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12
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Abstract
Patients with adult-onset autoimmune diabetes have less Human Leucocyte Antigen (HLA)-associated genetic risk and fewer diabetes-associated autoantibodies compared with patients with childhood-onset Type 1 diabetes. Metabolic changes at diagnosis reflect a broad clinical phenotype ranging from diabetic ketoacidosis to mild non-insulin-requiring diabetes, also known as latent autoimmune diabetes of the adult (LADA). This latter phenotype is the most prevalent form of adult-onset autoimmune diabetes and probably the most prevalent form of autoimmune diabetes in general. Although LADA is associated with the same genetic and immunological features as childhood-onset Type 1 diabetes, it also shares some genetic features with Type 2 diabetes, which raises the question of genetic heterogeneity predisposing to this form of the disease. The potential value of screening patients with adult-onset diabetes for diabetes-associated autoantibodies to identify those with LADA is emphasized by their lack of clinically distinct features, their different natural history compared with Type 2 diabetes and their potential need for a dedicated management strategy. The fact that, in some studies, patients with LADA show worse glucose control than patients with Type 2 diabetes, highlights the need for further therapeutic studies. Challenges regarding classification, epidemiology, genetics, metabolism, immunology, clinical presentation and treatment of LADA were discussed at a 2014 workshop arranged by the Danish Diabetes Academy. The presentations and discussions are summarized in this review, which sets out the current ideas and controversies surrounding this form of diabetes.
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Affiliation(s)
- E Laugesen
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
- Department of Endocrinology and Internal Medicine, Aarhus University Hospital, Aarhus, Denmark
- The Danish Diabetes Academy, Odense, Denmark
| | - J A Østergaard
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
- Department of Endocrinology and Internal Medicine, Aarhus University Hospital, Aarhus, Denmark
- The Danish Diabetes Academy, Odense, Denmark
| | - R D G Leslie
- Centre for Diabetes, The Blizard Institute, London, UK
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13
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Andersen MK, Sterner M, Forsén T, Käräjämäki A, Rolandsson O, Forsblom C, Groop PH, Lahti K, Nilsson PM, Groop L, Tuomi T. Type 2 diabetes susceptibility gene variants predispose to adult-onset autoimmune diabetes. Diabetologia 2014; 57:1859-68. [PMID: 24906951 DOI: 10.1007/s00125-014-3287-8] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/24/2014] [Accepted: 05/13/2014] [Indexed: 01/14/2023]
Abstract
AIMS/HYPOTHESIS Latent autoimmune diabetes in adults (LADA) is phenotypically a hybrid of type 1 and type 2 diabetes. Genetically LADA is poorly characterised but does share genetic predisposition with type 1 diabetes. We aimed to improve the genetic characterisation of LADA and hypothesised that type 2 diabetes-associated gene variants also predispose to LADA, and that the associations would be strongest in LADA patients with low levels of GAD autoantibodies (GADA). METHODS We assessed 41 type 2 diabetes-associated gene variants in Finnish (phase I) and Swedish (phase II) patients with LADA (n = 911) or type 1 diabetes (n = 406), all diagnosed after the age of 35 years, as well as in non-diabetic control individuals 40 years or older (n = 4,002). RESULTS Variants in the ZMIZ1 (rs12571751, p = 4.1 × 10(-5)) and TCF7L2 (rs7903146, p = 5.8 × 10(-4)) loci were strongly associated with LADA. Variants in the KCNQ1 (rs2237895, p = 0.0012), HHEX (rs1111875, p = 0.0024 in Finns) and MTNR1B (rs10830963, p = 0.0039) loci showed the strongest association in patients with low GADA, supporting the hypothesis that the disease in these patients is more like type 2 diabetes. In contrast, variants in the KLHDC5 (rs10842994, p = 9.5 × 10(-4) in Finns), TP53INP1 (rs896854, p = 0.005), CDKAL1 (rs7756992, p = 7.0 × 10(-4); rs7754840, p = 8.8 × 10(-4)) and PROX1 (rs340874, p = 0.003) loci showed the strongest association in patients with high GADA. For type 1 diabetes, a strong association was seen for MTNR1B (rs10830963, p = 3.2 × 10(-6)) and HNF1A (rs2650000, p = 0.0012). CONCLUSIONS/INTERPRETATION LADA and adult-onset type 1 diabetes share genetic risk variants with type 2 diabetes, supporting the idea of a hybrid form of diabetes and distinguishing them from patients with classical young-onset type 1 diabetes.
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Affiliation(s)
- Mette K Andersen
- Research Programs Unit, Diabetes and Obesity, University of Helsinki, Helsinki, Finland,
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14
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Abstract
Despite the notion that there is a degree of commonality to the biological etiology of type 1 diabetes (T1D) and type 2 diabetes (T2D), the lack of overlap in the genetic factors underpinning each of them suggests very distinct mechanisms. A disorder considered to be at the "intersection" of these two diseases is "latent autoimmune diabetes in adults" (LADA). Interestingly, genetic signals from both T1D and T2D are also seen in LADA, including the key HLA and transcription factor 7-like 2 (TCF7L2) loci, but the magnitudes of these effects are more complex than just pointing to LADA as being a simple admixture of T1D and T2D. We review the current status of the understanding of the genetics of LADA and place it in the context of what is known about the genetics of its better-studied "cousins," T1D and T2D, especially with respect to the myriad of discoveries made over the last decade through genome-wide association studies.
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Affiliation(s)
- Kevin J Basile
- Division of Human Genetics, Children's Hospital of Philadelphia, Philadelphia, PA, 19104, USA
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Winkler C, Raab J, Grallert H, Ziegler AG. Lack of association of type 2 diabetes susceptibility genotypes and body weight on the development of islet autoimmunity and type 1 diabetes. PLoS One. 2012;7:e35410. [PMID: 22558147 PMCID: PMC3338842 DOI: 10.1371/journal.pone.0035410] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2012] [Accepted: 03/15/2012] [Indexed: 12/11/2022] Open
Abstract
AIM To investigate whether type 2 diabetes susceptibility genes and body weight influence the development of islet autoantibodies and the rate of progression to type 1 diabetes. METHODS Genotyping for single nucleotide polymorphisms (SNP) of the type 2 diabetes susceptibility genes CDKAL1, CDKN2A/2B, FTO, HHEX-IDE, HMGA2, IGF2BP2, KCNJ11, KCNQ1, MTNR1B, PPARG, SLC30A8 and TCF7L2 was obtained in 1350 children from parents with type 1 diabetes participating in the BABYDIAB study. Children were prospectively followed from birth for islet autoantibodies and type 1 diabetes. Data on weight and height were obtained at 9 months, 2, 5, 8, 11, and 14 years of age. RESULTS None of type 2 diabetes risk alleles at the CDKAL1, CDKN2A/2B, FTO, HHEX-IDE, HMGA2, IGF2BP2, KCNJ11, KCNQ1, MTNR1B, PPARG and SLC30A8 loci were associated with the development of islet autoantibodies or diabetes. The type 2 diabetes susceptible genotype of TCF7L2 was associated with a lower risk of islet autoantibodies (7% vs. 12% by age of 10 years, P = 0.015, P(corrected) = 0.18). Overweight children at seroconversion did not progress to diabetes faster than non-overweight children (HR: 1.08; 95% CI: 0.48-2.45, P>0.05). CONCLUSIONS These findings do not support an association of type 2 diabetes risk factors with islet autoimmunity or acceleration of diabetes in children with a family history of type 1 diabetes.
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Lukacs K, Hosszufalusi N, Dinya E, Bakacs M, Madacsy L, Panczel P. The type 2 diabetes-associated variant in TCF7L2 is associated with latent autoimmune diabetes in adult Europeans and the gene effect is modified by obesity: a meta-analysis and an individual study. Diabetologia 2012; 55:689-93. [PMID: 22109281 DOI: 10.1007/s00125-011-2378-z] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/15/2011] [Accepted: 10/28/2011] [Indexed: 12/20/2022]
Abstract
AIMS/HYPOTHESIS The variants of transcription factor 7-like 2 (TCF7L2) gene have been proposed to be associated with latent autoimmune diabetes in adults (LADA). We sought to confirm the possible association in Europeans and to examine the interaction between one gene variant and clinical data. METHODS The TCF7L2 rs7903146 C-to-T polymorphism was genotyped in 211 LADA, 1,297 type 2 diabetic, 545 type 1 diabetic and 1,497 control individuals from Hungary. A meta-analysis of our and previously published studies was performed to evaluate the size and the heterogeneity of the gene effect. RESULTS The meta-analysis yielded a significant effect of TCF7L2 T allele (OR 1.28; p < 0.0001) on LADA risk without heterogeneity among Europeans. The T allele conferred equally strong susceptibility to LADA and type 2 diabetes. In the Hungarian dataset, the T allele was associated with LADA and type 2 diabetes, but not with type 1 diabetes. T allele carriers had significantly lower BMI than patients with the CC genotype in the LADA and type 2 diabetes groups (p = 0.0021 and p = 0.0013, respectively). In both diseases, the diabetes risk was significantly higher in the non-overweight than in the overweight BMI category (p = 0.0013 and p < 0.0001, respectively); susceptibility to LADA was increased by 2.84-fold in non-overweight individuals compared with overweight ones. CONCLUSIONS/INTERPRETATION The meta-analysis demonstrates that TCF7L2 rs7903146 polymorphism is a population-independent susceptibility locus for LADA in Europeans. The effect size is similar for LADA and type 2 diabetes. The gene effect on diabetes risk may be modulated by BMI, such that the lower the BMI, the higher the gene effect.
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Affiliation(s)
- K Lukacs
- 1st Department of Paediatrics, Semmelweis University, Bókay u 53-54, 1083 Budapest, Hungary.
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Abstract
The global obesity epidemic has led to dramatic increases in the incidence and prevalence of type 2 diabetes mellitus (T2DM) among youth worldwide. In today's clinical practice it has become increasingly difficult to distinguish type 1 diabetes mellitus (T1DM) from T2DM as many children with T1DM are overweight at diagnosis. Numerous recent publications note a significant proportion of physician-diagnosed T2DM youth with evidence of pancreatic autoimmunity, exemplifying the challenges in distinguishing between T1DM and T2DM. The clinical implications of the phenomenon of antibody positivity in phenotypic T2DM youth, also referred to as "type 1.5 diabetes" (T1.5 DM), "double diabetes," "latent autoimmune diabetes in youth" (LADY), and "hybrid diabetes," are unclear at present. Current and future work should determine if the presence of autoantibodies in phenotypic T2DM youth/children affects clinical course; this will facilitate the development of optimal treatment strategies.
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Affiliation(s)
- Angela Badaru
- Department of Pediatrics, University of Washington, Seattle, WA, USA.
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Hakonarson H, Grant SFA. Genome-wide association studies (GWAS): impact on elucidating the aetiology of diabetes. Diabetes Metab Res Rev 2011; 27:685-96. [PMID: 21630414 DOI: 10.1002/dmrr.1221] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/04/2011] [Accepted: 05/18/2011] [Indexed: 12/16/2022]
Abstract
It has proven to be challenging to isolate the genes underlying the genetic components conferring susceptibility to type 1 and type 2 diabetes. Unlike previous approaches, 'genome-wide association studies' have extensively delivered on the promise of uncovering genetic determinants of complex diseases, with a number of novel disease-associated variants being largely replicated by independent groups. This review provides an overview of these recent breakthroughs in the context of type 1 and type 2 diabetes, and outlines strategies on how these findings will be applied to impact clinical care for these two highly prevalent disorders.
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Affiliation(s)
- Hakon Hakonarson
- Center for Applied Genomics and Division of Human Genetics, Abramson Research Center of the Joseph Stokes Jr. Research Institute, Children's Hospital of Philadelphia, PA 19104-4318, USA; Department of Pediatrics, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA
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Abstract
It is well established that genetic diversity combined with specific environmental exposures contributes to disease susceptibility. However, it has turned out to be challenging to isolate the genes underlying the genetic component conferring susceptibility to most complex disorders. Traditional candidate gene and family-based linkage studies, which dominated gene discovery efforts for many years, were largely unsuccessful in unraveling the genetics of these traits due to the relatively limited information gained. Within the last 5 years, new advances in high-throughput methods have allowed for large volumes of single nucleotide polymorphisms (SNPs) throughout the genome to be genotyped across large and comprehensively phenotyped patient cohorts. Unlike previous approaches, these 'genome-wide association studies' (GWAS) have extensively delivered on the promise of uncovering genetic determinants of complex diseases, with hundreds of novel disease-associated variants being largely replicated by independent groups. This review provides an overview of these recent breakthroughs in the context of the pitfalls and challenges related to designing and carrying out a successful GWAS.
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Affiliation(s)
- Hakon Hakonarson
- The Center for Applied Genomics and Division of Human Genetics, The Children's Hospital of Philadelphia Research Institute, PA, USA.
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Vacante M, Malaguarnera M, Motta M. Revision of the ADA-classification of diabetes mellitus type 2 (DMT2): the importance of maturity onset diabetes (MOD), and senile diabetes (DS). Arch Gerontol Geriatr 2010; 53:113-9. [PMID: 20800300 DOI: 10.1016/j.archger.2010.06.017] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2010] [Revised: 06/22/2010] [Accepted: 06/26/2010] [Indexed: 02/06/2023]
Abstract
The changing social and economic conditions and the increase of the life span induced a progressive increase of the general prevalence of DMT2, particularly in the elderly population of the highly evoluted countries. Up to now 18 genetic loci have been identified, each of them consisting of several single nucleotide polymorphisms (SNPs). The evidence that the DMT2 is regulated by a high number of genes, demonstrate the pathogenetic complexity of this disease. The onset of diabetes mellitus (DM) in medium age is a consequence of the breakdown of the glycemic homeostasis in correlation with the genetic factors, such as the variants of the TCF7L2, obesity, etc., and the environmental factors, such as the life-style, the evolution of chronic-degenerative diseases, etc. In case of DM that onsets in old age we have to add the deterioration of the anti-aging defense mechanisms, characterized by the antagonistic action of the genes of longevity and aging. One can observe several clinical and therapeutic differences; therefore, the authors of this review propose the reinsertion of three forms into the DMT2 correlated with the age of onset and with the actual age of the subjects: the maturity onset diabetes (MOD), the maturity onset diabetes in elderly (MODE), and the senile diabetes (DS).
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Affiliation(s)
- Marco Vacante
- Department of Senescence, Urological and Neurological Sciences, University of Catania, Ospedale Cannizzaro, Viale Messina, 829, I-95125 Catania, Italy
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Zampetti S, Spoletini M, Petrone A, Capizzi M, Arpi ML, Tiberti C, Di Pietro S, Bosi E, Pozzilli P, Giorgino F, Buzzetti R. Association of TCF7L2 gene variants with low GAD autoantibody titre in LADA subjects (NIRAD Study 5). Diabet Med 2010; 27:701-4. [PMID: 20546291 DOI: 10.1111/j.1464-5491.2010.02997.x] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
AIMS We previously demonstrated the presence of two different populations among adult-onset autoimmune diabetes (latent autoimmume diabetes of adults; LADA) having high or low titre of antibodies to glutamic acid decarboxylase (GADA). The transcription factor 7-like 2 (TCF7L2) gene has been recognized as the major gene associated with Type 2 diabetes. The aim of the present study was to evaluate whether the phenotypic heterogeneity of LADA based on GADA titre is associated with TCF7L2 polymorphisms. METHODS Two hundred and fifty patients identified as LADA, divided into two subgroups with low (< or = 32 arbitrary units) or high (> 32 units) GADA titre, 620 subjects with Type 2 diabetes [from the Non-Insulin Requiring Autoimmune Diabetes (NIRAD) study cohort of 5330 subjects] in addition to 551 consecutive cases of Type 1 diabetes and 545 normoglycaemic subjects were analysed for the rs12255372 and rs7903146 polymorphisms of the TCF7L2 gene using Taqman. RESULTS The genotype and allele distributions of the two polymorphisms revealed similar frequencies in subjects with low GADA titre and Type 2 diabetes. High GADA titre, Type 1 diabetes and controls also showed comparable frequencies. A significant increase of GT/TT genotypes of the rs12255372 single-nucleotide polymorphism (SNP) and CT/TT genotypes of the rs7903146 SNP was observed in low GADA titre and Type 2 diabetes compared with high GADA titre, Type 1 diabetes and controls (P < or = 0.04 for both comparisons). The risk alleles of both variants were increased in low GADA titre and Type 2 diabetes compared with high GADA titre, Type 1 diabetes and control subjects (P < 0.02 for all comparisons). CONCLUSIONS TCF7L2 common genetic variants of susceptibility are associated only with low GADA antibody titre in LADA patients.
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Affiliation(s)
- S Zampetti
- Department of Clinical Sciences, Sapienza University, Rome, Italy
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Abstract
The Banting Medal for Scientific Achievement Award is the American Diabetes Association's highest scientific award and honors an individual who has made significant, long-term contributions to the understanding of diabetes, its treatment, and/or prevention. The award is named after Nobel Prize winner Sir Frederick Banting, who codiscovered insulin treatment for diabetes. Dr. Eisenbarth received the American Diabetes Association's Banting Medal for Scientific Achievement at the Association's 69th Scientific Sessions, June 5–9, 2009, in New Orleans, Louisiana. He presented the Banting Lecture, An Unfinished Journey—Type 1 Diabetes—Molecular Pathogenesis to Prevention , on Sunday, June 7, 2009.
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Affiliation(s)
- George S Eisenbarth
- Barbara Davis Center for Childhood Diabetes, University of Colorado Health Sciences Center, Aurora, Colorado, USA.
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Abstract
The pathophysiology of latent autoimmune diabetes in adults (LADA) is considered less understood than its much better characterized counterparts of type 1 and type 2 diabetes (T1D and T2D), where its clinical presentation exhibits some features of each of these two main diseases, earning it a reputation as being "type 1.5 diabetes". The etiology of LADA remains unknown, but a genetic component has been implicated from recent reports of T1D and T2D genes playing a role in its pathogenesis. One way to shed much needed light on the classification of LADA is to determine the discrete genetic factors conferring risk to the pathogenesis of this specific phenotype and to determine to what extent LADA shares genetic similarities with T1D and T2D. For instance, no conclusive support for a role of the T1D-associated INS gene has been reported in T2D; conversely, but similarly, no evidence has been found for the role of the T2D-associated genes IDE/HHEX, SLC30A8, CDKAL1, CDKN2A/B, IGF2BP2, FTO, and TCF7L2 in T1D. However, and somewhat at odds with current thinking, TCF7L2, the most strongly associated gene with T2D to date, is strongly associated with LADA, a disorder considered by the World Health Organization to be a slowly progressing form of T1D. In this review, we address recent advances in the genetics of T1D and T2D and how such discoveries have in turn shed some light on the genetics of LADA as being potentially at the "genetic intersection" of these two major diseases.
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Affiliation(s)
- Struan F A Grant
- Department of Pediatrics, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104, USA.
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Szepietowska B, Moczulski D, Wawrusiewicz-Kurylonek N, Grzeszczak W, Gorska M, Szelachowska M. Transcription factor 7-like 2-gene polymorphism is related to fasting C peptide in latent autoimmune diabetes in adults (LADA). Acta Diabetol 2010; 47:83-6. [PMID: 19533015 DOI: 10.1007/s00592-009-0133-4] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/26/2009] [Accepted: 05/27/2009] [Indexed: 12/12/2022]
Abstract
Common polymorphisms in the transcription factor 7-like 2 gene (TCF7L2) have been associated with type 2 diabetes in different populations and recently with LADA, but not with type 1 diabetes. The aim of our study was to investigate association between the rs7903146 polymorphism in the TCF7L2 gene and LADA in Polish patients. Link between the "high risk for type 2 diabetes genotype" with clinical features was analyzed. 68 newly diagnosed patients with LADA and 195 healthy controls were genotyped for the rs7903146 polymorphism in the TCF7L2 gene using the PCR-based RFLP method. Fasting C peptide level was measured by ELISA. We observed increased frequencies of the TT genotype of the rs7903146 polymorphism in the TCF7L2 gene in LADA patients compared to controls (15 vs. 6%, P = 0.03). Fasting C peptide serum concentration was significantly lower in group of patients with LADA carrying the TT genotype (P < 0.01). In conclusion, the data from this study confirmed previous results showing genetic similarities between patients with LADA and type 2 diabetes. Non-autoimmune mechanism may be related to beta cell dysfunction in patients with LADA.
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Affiliation(s)
- Barbara Szepietowska
- Section of Endocrinology, Department of Internal Medicine, Yale University School of Medicine, New Haven, CT, USA.
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26
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Raj SM, Howson JMM, Walker NM, Cooper JD, Smyth DJ, Field SF, Stevens HE, Todd JA. No association of multiple type 2 diabetes loci with type 1 diabetes. Diabetologia 2009; 52:2109-16. [PMID: 19455305 PMCID: PMC2738846 DOI: 10.1007/s00125-009-1391-y] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/09/2008] [Accepted: 04/16/2009] [Indexed: 01/29/2023]
Abstract
AIMS/HYPOTHESIS We used recently confirmed type 2 diabetes gene regions to investigate the genetic relationship between type 1 and type 2 diabetes, in an average of 7,606 type 1 diabetic individuals and 8,218 controls, providing >80% power to detect effects as small as an OR of 1.11 at a false-positive rate of 0.003. METHODS The single nucleotide polymorphisms (SNPs) with the most convincing evidence of association in 12 type 2 diabetes-associated gene regions, PPARG, CDKAL1, HNF1B, WFS1, SLC30A8, CDKN2A-CDKN2B, IGF2BP2, KCNJ11, TCF7L2, FTO, HHEX-IDE and THADA, were analysed in type 1 diabetes cases and controls. PPARG and HHEX-IDE were additionally tested for association in 3,851 type 1 diabetes families. Tests for interaction with HLA class II genotypes, autoantibody status, sex, and age-at-diagnosis of type 1 diabetes were performed with all 12 gene regions. RESULTS Only PPARG and HHEX-IDE showed any evidence of association with type 1 diabetes cases and controls (p = 0.004 and p = 0.003, respectively; p > 0.05 for other SNPs). The potential association of PPARG was supported by family analyses (p = 0.003; p (combined) = 1.0 x 10(-4)). No SNPs showed evidence of interaction with any covariate (p > 0.05). CONCLUSIONS/INTERPRETATION We found no convincing genetic link between type 1 and type 2 diabetes. An association of PPARG (rs1801282/Pro12Ala) could be consistent with its known function in inflammation. Hence, our results reinforce evidence suggesting that type 1 diabetes is a disease of the immune system, rather than being due to inherited defects in beta cell function or regeneration or insulin resistance.
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Affiliation(s)
- S. M. Raj
- Juvenile Diabetes Research Foundation/Wellcome Trust Diabetes and Inflammation Laboratory, Cambridge Institute for Medical Research, University of Cambridge, Wellcome Trust/MRC building, Hills Road, Cambridge, CB2 0XY UK
| | - J. M. M. Howson
- Juvenile Diabetes Research Foundation/Wellcome Trust Diabetes and Inflammation Laboratory, Cambridge Institute for Medical Research, University of Cambridge, Wellcome Trust/MRC building, Hills Road, Cambridge, CB2 0XY UK
| | - N. M. Walker
- Juvenile Diabetes Research Foundation/Wellcome Trust Diabetes and Inflammation Laboratory, Cambridge Institute for Medical Research, University of Cambridge, Wellcome Trust/MRC building, Hills Road, Cambridge, CB2 0XY UK
| | - J. D. Cooper
- Juvenile Diabetes Research Foundation/Wellcome Trust Diabetes and Inflammation Laboratory, Cambridge Institute for Medical Research, University of Cambridge, Wellcome Trust/MRC building, Hills Road, Cambridge, CB2 0XY UK
| | - D. J. Smyth
- Juvenile Diabetes Research Foundation/Wellcome Trust Diabetes and Inflammation Laboratory, Cambridge Institute for Medical Research, University of Cambridge, Wellcome Trust/MRC building, Hills Road, Cambridge, CB2 0XY UK
| | - S. F. Field
- Juvenile Diabetes Research Foundation/Wellcome Trust Diabetes and Inflammation Laboratory, Cambridge Institute for Medical Research, University of Cambridge, Wellcome Trust/MRC building, Hills Road, Cambridge, CB2 0XY UK
| | - H. E. Stevens
- Juvenile Diabetes Research Foundation/Wellcome Trust Diabetes and Inflammation Laboratory, Cambridge Institute for Medical Research, University of Cambridge, Wellcome Trust/MRC building, Hills Road, Cambridge, CB2 0XY UK
| | - J. A. Todd
- Juvenile Diabetes Research Foundation/Wellcome Trust Diabetes and Inflammation Laboratory, Cambridge Institute for Medical Research, University of Cambridge, Wellcome Trust/MRC building, Hills Road, Cambridge, CB2 0XY UK
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Affiliation(s)
- K R Owen
- Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, Churchill Hospital, Headington, UK
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Nagy G, Kovacs-Nagy R, Kereszturi E, Somogyi A, Szekely A, Nemeth N, Hosszufalusi N, Panczel P, Ronai Z, Sasvari-Szekely M. Association of hypoxia inducible factor-1 alpha gene polymorphism with both type 1 and type 2 diabetes in a Caucasian (Hungarian) sample. BMC Med Genet 2009; 10:79. [PMID: 19691832 PMCID: PMC2736933 DOI: 10.1186/1471-2350-10-79] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/05/2009] [Accepted: 08/19/2009] [Indexed: 12/20/2022]
Abstract
Background Hypoxia inducible factor-1 alpha (HIF-1α) is a transcription factor that plays an important role in neo-vascularisation, embryonic pancreas beta-cell mass development, and beta cell protection. Recently a non synonymous single nucleotide polymorphism (g.C45035T SNP, rs11549465) of HIF-1α gene, resulting in the p.P582S amino acid change has been shown to be associated with type 2 diabetes (T2DM) in a Japanese population. Our aim was to replicate these findings on a Caucasian (Hungarian) population, as well as to study whether this genetic effect is restricted to T2DM or can be expanded to diabetes in general. Methods A large Caucasian sample (N = 890) was recruited including 370 T2DM, 166 T1DM and 354 healthy subjects. Genotyping was validated by two independent methods: a restriction fragment analysis (RFLP) and a real time PCR using TaqMan probes. An overestimation of heterozygotes by RFLP was observed as a consequence of a nearby SNP (rs34005929). Therefore genotyping results of the justified TaqMan system were accepted. The measured genotype distribution corresponded to Hardy-Weinberg equilibrium (P = 0.740) Results As the TT genotype was extremely rare in the population (0.6% in clinical sample and 2.5% in controls), the genotypes were grouped as T absent (CC) and T present (CT and TT). Genotype-wise analysis showed a significant increase of T present group in controls (24.0%) as compared to patients (16.8%, P = 0.008). This genetic effect was demonstrated in the separated samples of type 1 (15.1%, P = 0.020), and also in type 2 (17.6%, P = 0.032) diabetes. Allele-wise analysis gave identical results showing a higher frequency of the T allele in the control sample (13.3%) than in the clinical sample (8.7%, P = 0.002) with similar results in type 1 (7.8%, P = 0.010) and type 2 (9.1%, P = 0.011) diabetes. The odds ratio for diabetes (either type 1 or 2) was 1.56 in the presence of the C allele. Conclusion We confirmed the protective effect of a rare genetic variant of HIF-1α gene against type 2 diabetes in a Caucasian sample. Moreover we demonstrated a genetic contribution of the same polymorphism in type 1 diabetes as well, supporting a possible overlap in pathomechanism for T2DM and a T1DM.
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Affiliation(s)
- Geza Nagy
- 2nd Department of Internal Medicine, Semmelweis University, Budapest, Hungary.
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Wilkin TJ. The accelerator hypothesis: a review of the evidence for insulin resistance as the basis for type I as well as type II diabetes. Int J Obes (Lond). 2009;33:716-726. [PMID: 19506563 DOI: 10.1038/ijo.2009.97] [Citation(s) in RCA: 105] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Although some 40 years have passed since type I diabetes was first defined, its cause remains unknown. The autoimmunity paradigm of immune dysregulation has not offered an explanation for its rising incidence, nor means of preventing it, and there is arguably good reason to consider alternatives. The accelerator hypothesis is a singular, unifying concept that argues that type I and type II diabetes are the same disorder of insulin resistance, set against different genetic backgrounds. The hypothesis does not deny the role of autoimmuniy, only its primacy in the process. It distinguishes type I and type II diabetes only by tempo, the faster tempo reflecting the more susceptible genotype and (inevitably) earlier presentation. Insulin resistance is closely related to the rise in overweight and obesity, a trend that the hypothesis deems central to the rising incidence of all diabetes in the developed and developing world. Rather than overlap between the two types of diabetes, the accelerator hypothesis envisages overlay-each a subset of the general population differing from each other only by genotype. Indeed, it views type I and type II diabetes as a continuum, where the infinitely variable interaction between insulin resistance and genetic response determines the age at which beta-cell loss becomes critical. Adult diabetes is not viewed as an entity, but rather as diabetes presenting in adulthood. Childhood diabetes, similarly, is diabetes presenting in childhood. The increasing incidence of both is primarily the result of lifestyle change and the rise in body weight that has resulted.
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Abstract
Type 1 diabetes (T1D) is a chronic disease that typically manifests itself in childhood through the autoimmune destruction of pancreatic beta cells, resulting in a lack of production of insulin. T1D is a multifactorial disease with a strong genetic component that is thought to interact with specific environmental triggers. Several genetic determinants of T1D were already established before the era of genome-wide association studies, primarily with the HLA class II genes, encoding highly polymorphic antigen-presenting proteins that account for almost 50% of the genetic risk for T1D. The recent development of high-throughput single nucleotide polymorphism genotyping array technologies has enabled investigators to perform high-density genome-wide association studies in search of the remaining T1D loci. Combined with the well-established genes known for many years, 16 loci have now been uncovered to date as being robustly associated with the pathogenesis of this phenotype.
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Affiliation(s)
- Struan F A Grant
- Center for Applied Genomics, 1216E Abramson Research Center, 3615 Civic Center Boulevard, Philadelphia, PA 19104-4318, USA
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Yu J, Steck AK, Babu S, Yu L, Miao D, McFann K, Hutton J, Eisenbarth GS, Klingensmith G. Single nucleotide transcription factor 7-like 2 (TCF7L2) gene polymorphisms in antiislet autoantibody-negative patients at onset of diabetes. J Clin Endocrinol Metab 2009; 94:504-10. [PMID: 19050058 PMCID: PMC2646512 DOI: 10.1210/jc.2007-2694] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
CONTEXT There is controversy as to whether type 2 diabetes genetic susceptibility contributes to type 1 diabetes, and it is not known what proportion of islet autoantibody-negative new onset subjects have type 2 diabetes risk alleles. OBJECTIVES We designed this study to evaluate whether two type 2 diabetes-associated single nucleotide polymorphisms (SNPs) of transcription factor 7-like 2 (TCF7L2) gene are associated with the development of islet autoantibody-negative diabetes vs. islet autoantibody-positive diabetes in young patients and whether these SNPs are associated with specific clinical phenotypes. DESIGN Autoantibody against glutamic acid decarboxylase 65, islet cell antibody 512bdc (form of IA-2), insulin, ZnT8 transporter, and cytoplasmic islet cell antibody were assayed in patients with new onset diabetes seen at the Barbara Davis Center using sera obtained within 2 wk of diagnosis. We genotyped two noncoding variants in the TCF7L2 gene, rs12255372 and rs7903146, in diabetic subjects and normal controls. RESULTS A total of 140 patients (15.7%) were negative for all islet autoantibodies among 893 subjects less than age 25 at the onset of diabetes. The allele and genotype frequencies of two SNPs showed that these are associated (odds ratio up to 4) with the development of diabetes in the autoantibody-negative diabetic cohort, but not in the autoantibody-positive diabetic cohort. CONCLUSION TCF7L2 type 2 diabetes susceptibility alleles are associated with islet autoantibody-negative but not autoantibody-positive new onset diabetes in young patients.
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Affiliation(s)
- Jeesuk Yu
- University of Colorado Health Sciences Center, Aurora, Colorado, USA.
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Bakhtadze E, Cervin C, Lindholm E, Borg H, Nilsson P, Arnqvist HJ, Bolinder J, Eriksson JW, Gudbjörnsdottir S, Nyström L, Agardh CD, Landin-Olsson M, Sundkvist G, Groop LC. Common variants in the TCF7L2 gene help to differentiate autoimmune from non-autoimmune diabetes in young (15-34 years) but not in middle-aged (40-59 years) diabetic patients. Diabetologia 2008; 51:2224-32. [PMID: 18839133 DOI: 10.1007/s00125-008-1161-2] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/11/2008] [Accepted: 08/20/2008] [Indexed: 02/05/2023]
Abstract
AIMS/HYPOTHESIS Type 1 diabetes in children is characterised by autoimmune destruction of pancreatic beta cells and the presence of certain risk genotypes. In adults the same situation is often referred to as latent autoimmune diabetes in adults (LADA). We tested whether genetic markers associated with type 1 or type 2 diabetes could help to discriminate between autoimmune and non-autoimmune diabetes in young (15-34 years) and middle-aged (40-59 years) diabetic patients. METHODS In 1,642 young and 1,619 middle-aged patients we determined: (1) HLA-DQB1 genotypes; (2) PTPN22 and INS variable-number tandem repeat (VNTR) polymorphisms; (3) two single nucleotide polymorphisms (rs7903146 and rs10885406) in the TCF7L2 gene; (4) glutamic acid decarboxylase (GAD) and IA-2-protein tyrosine phosphatase-like protein (IA-2) antibodies; and (5) fasting plasma C-peptide. RESULTS Frequency of risk genotypes HLA-DQB1 (60% vs 25%, p = 9.4 x 10(-34); 45% vs 18%, p = 1.4 x 10(-16)), PTPN22 CT/TT (34% vs 26%, p = 0.0023; 31% vs 23%, p = 0.034), INS VNTR class I/I (69% vs 53%, p = 1.3 x 10(-8); 69% vs 51%, p = 8.5 x 10(-5)) and INS VNTR class IIIA/IIIA (75% vs 63%, p = 4.3 x 10(-6); 73% vs 60%, p = 0.008) was increased in young and middle-aged GAD antibodies (GADA)-positive compared with GADA-negative patients. The type 2 diabetes-associated genotypes of TCF7L2 CT/TT of rs7903146 were significantly more common in young GADA-negative than in GADA-positive patients (53% vs 43%; p = 0.0004). No such difference was seen in middle-aged patients, in whom the frequency of the CT/TT genotypes of TCF7L2 was similarly increased in GADA-negative and GADA-positive groups (55% vs 56%). CONCLUSIONS/INTERPRETATION Common variants in the TCF7L2 gene help to differentiate young but not middle-aged GADA-positive and GADA-negative diabetic patients, suggesting that young GADA-negative patients have type 2 diabetes and that middle-aged GADA-positive patients are different from their young GADA-positive counterparts and share genetic features with type 2 diabetes.
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Affiliation(s)
- E Bakhtadze
- Department of Clinical Sciences-Diabetes and Endocrinology, Lund University Diabetes Center, Malmö, Sweden.
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Rafiq S, Melzer D, Weedon MN, Lango H, Saxena R, Scott LJ, Palmer CNA, Morris AD, McCarthy MI, Ferrucci L, Hattersley AT, Zeggini E, Frayling TM. Gene variants influencing measures of inflammation or predisposing to autoimmune and inflammatory diseases are not associated with the risk of type 2 diabetes. Diabetologia 2008; 51:2205-13. [PMID: 18853133 PMCID: PMC2662689 DOI: 10.1007/s00125-008-1160-3] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/02/2008] [Accepted: 08/18/2008] [Indexed: 12/17/2022]
Abstract
AIMS/HYPOTHESIS There are strong associations between measures of inflammation and type 2 diabetes, but the causal directions of these associations are not known. We tested the hypothesis that common gene variants known to alter circulating levels of inflammatory proteins, or known to alter autoimmune-related disease risk, influence type 2 diabetes risk. METHODS We selected 46 variants: (1) eight variants known to alter circulating levels of inflammatory proteins, including those in the IL18, IL1RN, IL6R, MIF, PAI1 (also known as SERPINE1) and CRP genes; and (2) 38 variants known to predispose to autoimmune diseases, including type 1 diabetes. We tested the associations of these variants with type 2 diabetes using a meta-analysis of 4,107 cases and 5,187 controls from the Wellcome Trust Case Control Consortium, the Diabetes Genetics Initiative, and the Finland-United States Investigation of NIDDM studies. We followed up associated variants (p < 0.01) in a further set of 3,125 cases and 3,596 controls from the UK. RESULTS We found no evidence that inflammatory or autoimmune disease variants are associated with type 2 diabetes (at p <or= 0.01). The OR observed between the variant altering IL-18 levels, rs2250417, and type 2 diabetes (OR 1.00 [95% CI 0.99-1.03]), is much lower than that expected given (1) the effect of the variant on IL-18 levels (0.28 SDs per allele); and (2) estimates, based on other studies, of the correlation between IL-18 levels and type 2 diabetes risk (approximate OR 1.15 [95% CI 1.09-1.21] per 0.28 SD increase in IL-18 levels). CONCLUSIONS/INTERPRETATION Our study provided no evidence that variants known to alter measures of inflammation, autoimmune or inflammatory disease risk, including type 1 diabetes, alter type 2 diabetes risk.
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Affiliation(s)
- S Rafiq
- Peninsula Medical School, University of Exeter, Magdalen Road, Exeter, EX1 2LU, UK
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Rainbow DB, Esposito L, Howlett SK, Hunter KM, Todd JA, Peterson LB, Wicker LS. Commonality in the genetic control of Type 1 diabetes in humans and NOD mice: variants of genes in the IL-2 pathway are associated with autoimmune diabetes in both species. Biochem Soc Trans 2008; 36:312-5. [PMID: 18481948 DOI: 10.1042/BST0360312] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Variants within the IL-2 (interleukin 2) and CD25 genes are associated with T1DM (Type 1 diabetes mellitus) in mice and humans respectively. Both gene products are essential for optimal immune tolerance and a partial failure to tolerize is linked to the autoimmune responses to insulin and other beta-cell proteins that precede T1DM onset. Gene variants that contribute to common disease susceptibility often alter gene expression only modestly. Small expression changes can be technically challenging to measure robustly, especially since biological variation usually contributes negatively to this goal. The present review focuses on allele-specific expression assays that can be used to quantify genotype-determined expression differences such as those observed for IL-2, where the susceptibility allele is transcribed 2-fold less than the resistance allele.
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Mahurkar S, Bhaskar S, Reddy DN, Prakash S, Rao GV, Singh SP, Thomas V, Chandak GR. TCF7L2 gene polymorphisms do not predict susceptibility to diabetes in tropical calcific pancreatitis but may interact with SPINK1 and CTSB mutations in predicting diabetes. BMC Med Genet 2008; 9:80. [PMID: 18706099 PMCID: PMC2529279 DOI: 10.1186/1471-2350-9-80] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/21/2008] [Accepted: 08/16/2008] [Indexed: 12/22/2022]
Abstract
BACKGROUND Tropical calcific pancreatitis (TCP) is a type of chronic pancreatitis unique to developing countries in tropical regions and one of its important features is invariable progression to diabetes, a condition called fibro-calculous pancreatic diabetes (FCPD), but the nature of diabetes in TCP is controversial. We analysed the recently reported type 2 diabetes (T2D) associated polymorphisms in the TCF7L2 gene using a case-control approach, under the hypothesis that TCF7L2 variants should show similar association if diabetes in FCPD is similar to T2D. We also investigated the interaction between the TCF7L2 variants and N34S SPINK1 and L26V CTSB mutations, since they are strong predictors of risk for TCP. METHODS Two polymorphisms rs7903146 and rs12255372 in the TCF7L2 gene were analyzed by direct sequencing in 478 well-characterized TCP patients and 661 healthy controls of Dravidian and Indo-European ethnicities. Their association with TCP with diabetes (FCPD) and without diabetes was tested in both populations independently using chi-square test. Finally, a meta analysis was performed on all the cases and controls for assessing the overall significance irrespective of ethnicity. We dichotomized the whole cohort based on the presence or absence of N34S SPINK1 and L26V CTSB mutations and further subdivided them into TCP and FCPD patients and compared the distribution of TCF7L2 variants between them. RESULTS The allelic and genotypic frequencies for both TCF7L2 polymorphisms, did not differ significantly between TCP patients and controls belonging to either of the ethnic groups or taken together. No statistically significant association of the SNPs was observed with TCP or FCPD or between carriers and non-carriers of N34S SPINK1 and L26V CTSB mutations. The minor allele frequency for rs7903146 was different between TCP and FCPD patients carrying the N34S SPINK1 variant but did not reach statistical significance (OR = 1.59, 95% CI = 0.93-2.70, P = 0.09), while, TCF7L2variant showed a statistically significant association between TCP and FCPD patients carrying the 26V allele (OR = 1.69, 95% CI = 1.11-2.56, P = 0.013). CONCLUSION Type 2 diabetes associated TCF7L2 variants are not associated with diabetes in TCP. Since, TCF7L2 is a major susceptibility gene for T2D, it may be hypothesized that the diabetes in TCP patients may not be similar to T2D. Our data also suggests that co-existence of TCF7L2 variants and the SPINK1 and CTSB mutations, that predict susceptibility to exocrine damage, may interact to determine the onset of diabetes in TCP patients.
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Affiliation(s)
- Swapna Mahurkar
- Genome Research Group, Centre for Cellular and Molecular Biology, Uppal Road, Hyderabad, India
| | - Seema Bhaskar
- Genome Research Group, Centre for Cellular and Molecular Biology, Uppal Road, Hyderabad, India
| | | | - Swami Prakash
- Genome Research Group, Centre for Cellular and Molecular Biology, Uppal Road, Hyderabad, India
| | - G Venkat Rao
- Asian Institute of Gastroenterology, Punjagutta, Hyderabad, India
| | | | - Varghese Thomas
- Department of Gastroenterology, Calicut Medical College, Calicut, India
| | - Giriraj Ratan Chandak
- Genome Research Group, Centre for Cellular and Molecular Biology, Uppal Road, Hyderabad, India
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Gulcher J, Stefansson K. The clinical utility of genetic risk variants in type 2 diabetes. Expert Opin Med Diagn 2008; 2:991-1002. [PMID: 23495871 DOI: 10.1517/17530059.2.8.991] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
BACKGROUND Type 2 diabetes is one of the first success stories in the application of genome-wide linkage and association studies to find genetic variants contributing to its risk. OBJECTIVE Are the genetic markers found so far useful in predicting which individuals are more likely to develop type 2 diabetes? Can they find which patients with prediabetes are more likely to convert to type 2 diabetes and therefore may benefit the most from lifestyle or pharmacologic prevention strategies? METHODS The literature pertaining to the discovery and replications of genes contributing to type 2 diabetes was focused on. RESULTS/CONCLUSION Substantial risk for type 2 diabetes is represented by the top 8 genes, including TCF7L2, and in certain circumstances may be useful for prevention strategies targeted to those with highest risk.
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Affiliation(s)
- Jeff Gulcher
- Decode Genetics, Inc., Sturlugata 8, 101 Reykjavik, Iceland
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Abstract
PURPOSE OF REVIEW The purpose of this review is to provide a comprehensive evaluation of the most important type 2 diabetes gene to date, transcription factor 7 like-2. RECENT FINDINGS An important step to find genetic causes of type 2 diabetes in 2006 was the identification of the fact that variants in the gene encoding transcription factor 7 like-2 reproducibly increase susceptibility to type 2 diabetes in almost all populations studied. This gene has since then emerged as the most important type 2 diabetes gene. Genetic variants in transcription factor 7 like-2 confer a strong risk of type 2 diabetes possibly mediated by altering expression of transcription factor 7 like-2 in pancreatic islets. Risk variants in the transcription factor 7 like-2 influence insulin secretions both in vitro and in vivo. The risk T allele of this single nucleotide polymorphism also seems to have effects on the enteroinsular axis and the relationship between the incretin hormone glucose-dependent insulinotropic peptide and its target hormones, glucagon and insulin. Given transcription factor 7 like-2s' central role in the Wnt signaling pathway, it would be important to define whether the variant is associated with increased or decreased Wnt signaling. SUMMARY The fact that transcription factor 7 like-2 is by far the strongest type 2 diabetes susceptibility gene to date emphasizes the importance of exploring the potential of manipulating this pathway in future treatment of the disease.
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Affiliation(s)
- Valeriya Lyssenko
- Department of Clinical Sciences, Diabetes and Endocrinology, Lund University, Malmoe, Sweden.
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Brorsson C, Bergholdt R, Sjögren M, Eising S, Sørensen KM, Hougaard DM, Orho-Melander M, Groop L, Pociot F. A non-synonymous variant in SLC30A8 is not associated with type 1 diabetes in the Danish population. Mol Genet Metab 2008; 94:386-8. [PMID: 18400535 DOI: 10.1016/j.ymgme.2008.02.011] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/28/2008] [Accepted: 02/28/2008] [Indexed: 10/22/2022]
Abstract
Genome-wide association scans in type 2 diabetes (T2D) have identified a risk variant, rs13266634 (Arg325Trp), in SLC30A8 on chromosome 8. SLC30A8 encodes a beta-cell specific zinc-ion transporter and rs13266634 has been shown to affect insulin secretion. Recently, autoantibodies for Slc30A8 with high predictive value were demonstrated in individuals with type 1 diabetes (T1D), making this gene an interesting T1D candidate gene. We genotyped rs13266634 in 3008 cases and controls and 246 families from Denmark. Association to T1D could not be demonstrated.
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Affiliation(s)
- Caroline Brorsson
- Steno Diabetes Center, Niels Steensensvej 1, DK-2820 Gentofte, Denmark
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Qu HQ, Grant SF, Bradfield JP, Kim C, Frackelton E, Hakonarson H, Polychronakos C. Association analysis of type 2 diabetes Loci in type 1 diabetes. Diabetes 2008; 57:1983-6. [PMID: 18426861 PMCID: PMC2453613 DOI: 10.2337/db08-0270] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/24/2008] [Accepted: 04/15/2008] [Indexed: 01/14/2023]
Abstract
OBJECTIVE To search for a possible association of type 1 diabetes with 10 validated type 2 diabetes loci, i.e., PPARG, KCNJ11, WFS1, HNF1B, IDE/HHEX, SLC30A8, CDKAL1, CDKN2A/B, IGF2BP2, and FTO/RPGRIP1L. RESEARCH DESIGN AND METHODS Two European population samples were studied: 1) one case-control cohort of 514 type 1 diabetic subjects and 2,027 control subjects and 2) one family cohort of 483 complete type 1 diabetic case-parent trios (total 997 affected). A total of 13 tag single nucleotide polymorphisms (SNPs) from the 10 type 2 diabetes loci were analyzed for type 1 diabetes association. RESULTS No association of type 1 diabetes was found with any of the 10 type 2 diabetes loci, and no age-at-onset effect was detected. By combined analysis using the Wellcome Trust Case-Control Consortium type 1 diabetes data, SNP rs1412829 in the CDKN2A/B locus bordered on significance (P = 0.039) (odds ratio 0.929 [95% CI 0.867-0.995]), which did not reach the statistical significance threshold adjusted for 13 tests (alpha = 0.00385). CONCLUSIONS This study suggests that the type 2 diabetes loci do not play any obvious role in type 1 diabetes genetic susceptibility. The distinct molecular mechanisms of the two diseases highlighted the importance of differentiation diagnosis and different treatment principles.
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Affiliation(s)
- Hui-Qi Qu
- Departments of Pediatrics and Human Genetics, McGill University, Montreal, Québec, Canada
| | - Struan F.A. Grant
- Center for Applied Genomics, Philadelphia, Pennsylvania
- Department of Pediatrics and Division of Human Genetics, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania
| | | | - Cecilia Kim
- Center for Applied Genomics, Philadelphia, Pennsylvania
| | | | - Hakon Hakonarson
- Center for Applied Genomics, Philadelphia, Pennsylvania
- Department of Pediatrics and Division of Human Genetics, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania
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Abstract
The accelerator hypothesis was published in 2001, and proposes that that type 1 and type 2 diabetes are the same disorder of insulin resistance set against different genetic backgrounds. The different genes modulate (variably accelerate) the tempo of beta cell loss and thereby determine the age at onset and incidence of the disease. Some of the predictions made by the hypothesis have been met by data not available when the hypothesis was first proposed. Principle among these is the expectation - now born out in five independent studies - that age at onset should be inversely related to BMI, a surrogate for insulin resistance. This article updates the hypothesis, provides evidence to support the predictions and offers arguments to counter challenges that have appeared in print. Finally, it proposes a randomised controlled trial to test the principle that a reduction in blood glucose, by reducing the load on beta cells, will slow the tempo of their destruction and reduce the incidence of type 1 diabetes.
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Affiliation(s)
- Terence J Wilkin
- Department of Endocrinology & Metabolism, Peninsula Medical School, Plymouth, Devon, UK.
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Cervin C, Lyssenko V, Bakhtadze E, Lindholm E, Nilsson P, Tuomi T, Cilio CM, Groop L. Genetic similarities between latent autoimmune diabetes in adults, type 1 diabetes, and type 2 diabetes. Diabetes 2008; 57:1433-7. [PMID: 18310307 DOI: 10.2337/db07-0299] [Citation(s) in RCA: 173] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
OBJECTIVE Latent autoimmune diabetes in adults (LADA) is often considered a slowly progressing subtype of type 1 diabetes, although the clinical picture more resembles type 2 diabetes. One way to improve classification is to study whether LADA shares genetic features with type 1 and/or type 2 diabetes. RESEARCH DESIGN AND METHODS To accomplish this, we studied whether LADA shares variation in the HLA locus or INS VNTR and PTPN22 genes with type 1 diabetes or the TCF7L2 gene with type 2 diabetes in 361 LADA, 718 type 1 diabetic, and 1,676 type 2 diabetic patients, as well as 1,704 healthy control subjects from Sweden and Finland. RESULTS LADA subjects showed, compared with type 2 diabetic patients, increased frequency of risk for the HLA-DQB1 *0201/*0302 genotype (27 vs. 6.9%; P < 1 x 10(-6)), with similar frequency as with type 1 diabetes (36%). In addition, LADA subjects showed higher frequencies of protective HLA-DQB1 *0602(3)/X than type 1 diabetic patients (8.1 vs. 3.2%, P = 0.003). The AA genotype of rs689, referring to the class I allele in the INS VNTR, as well as the CT/TT genotypes of rs2476601 in the PTPN22 gene, were increased both in type 1 diabetic (P = 3 x 10(-14) and P = 1 x 10(-10), respectively) and LADA (P = 0.001 and P = 0.002) subjects compared with control subjects. Notably, the frequency of the type 2 diabetes-associated CT/TT genotypes of rs7903146 in the TCF7L2 were increased in LADA subjects (52.8%; P = 0.03), to the same extent as in type 2 diabetic subjects (54.1%, P = 3 x 10(-7)), compared with control subjects (44.8%) and type 1 diabetic subjects (43.3%). CONCLUSIONS LADA shares genetic features with both type 1 (HLA, INS VNTR, and PTPN22) and type 2 (TCF7L2) diabetes, which justifies considering LADA as an admixture of the two major types of diabetes.
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Affiliation(s)
- Camilla Cervin
- Department of Clinical Sciences-Diabetes & Endocrinology, Clinical Research Center, Malmö University Hospital, Lund University, S-205 02 Malmö, Sweden
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Affiliation(s)
- Andrea K Steck
- Barbara Davis Center for Childhood Diabetes, University of Colorado Health Sciences Center, Mail Stop B140, P.O. Box 6511, Aurora, CO 80045-6511, USA
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Abstract
Type 1 diabetes (T1D) comprises all forms of autoimmune-mediated and idiopathic beta-cell destruction leading to absolute insulin deficiency. The etiological heterogeneity of T1D has been recognized for the last decades, but it has been divided into only two subtypes so far: autoimmune (T1D)A and non-autoimmune (T1D)B mediated. Polygenic T1DA (isolated or associated to other autoimmune diseases) is the most prevalent type of T1D. T1DA might be part of rare monogenic syndromes related to mutations in the autoimmune regulator gene (AIRE) and FOXp3. Non-autoimmune forms of T1D correspond to approximately 4 to 7% of newly diagnosed T1D and include T1DB, as well as other types of atypical diabetes, for example fulminant type 1 diabetes and adult ketosis-prone diabetes. A new expression of diabetes in young with insulin resistance and obesity, along with the presence of pancreatic autoimmunity markers, namely auto-antibodies to islet cell antigens, is called double diabetes (DD), T1DA plus type 2 diabetes. Evidence has been collected concerning the potential effect of obesity-linked cytokines in amplifying the autoimmune response in DD. Therefore all these issues are presented and discussed in this review as the concept of heterogeneity of Type 1 Diabetes.
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Affiliation(s)
- Sergio Atala Dib
- Centro de Diabetes, Departamento de Medicina, Escola Paulista de Medicina, Universidade Federal de São Paulo SP, Brasil. sergio.dib@unifes
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Wilkin TJ. Comment on: Gale EAM (2007) To boldly go -- or to go too boldly? The accelerator hypothesis revisited. Diabetologia 50:1571-1575 -- a reply to the editor. Diabetologia 2007; 50:2604-6. [PMID: 17917712 DOI: 10.1007/s00125-007-0829-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/11/2007] [Accepted: 08/08/2007] [Indexed: 12/19/2022]
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Abstract
The goal of this paper is to illustrate the application of the tools of genetic epidemiology, particularly the family study method, to inform the classification of psychiatric disorders in adults and children. The first section describes family studies of adults designed to investigate the causes of comorbidity of anxiety and depression. The analysis of familial traits provides stronger evidence for the validity of certain sub-types of anxiety and mood disorders that co-occur within the same individual and within families. The second section presents an example of the use of the family study method to examine the validity of the autism spectrum disorders (ASD). A review of these studies suggests that the most consistently familial traits in ASD are language and communication skills, insistence on sameness and non-verbal IQ. These are also the traits most commonly associated with the differentiation of autism from Asperger disorder and PDDNOS using both cross-sectional and longitudinal studies. From these data, a new classification system of the ASDs is proposed based on these familial traits.
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Affiliation(s)
- Peter Szatmari
- Department of Psychiatry and Behavioural Neurosciences, McMaster University, Hamilton, Ontario, Canada.
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Meigs JB, Manning AK, Fox CS, Florez JC, Liu C, Cupples LA, Dupuis J. Genome-wide association with diabetes-related traits in the Framingham Heart Study. BMC Med Genet 2007; 8 Suppl 1:S16. [PMID: 17903298 PMCID: PMC1995610 DOI: 10.1186/1471-2350-8-s1-s16] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
BACKGROUND Susceptibility to type 2 diabetes may be conferred by genetic variants having modest effects on risk. Genome-wide fixed marker arrays offer a novel approach to detect these variants. METHODS We used the Affymetrix 100K SNP array in 1,087 Framingham Offspring Study family members to examine genetic associations with three diabetes-related quantitative glucose traits (fasting plasma glucose (FPG), hemoglobin A1c, 28-yr time-averaged FPG (tFPG)), three insulin traits (fasting insulin, HOMA-insulin resistance, and 0-120 min insulin sensitivity index); and with risk for diabetes. We used additive generalized estimating equations (GEE) and family-based association test (FBAT) models to test associations of SNP genotypes with sex-age-age2-adjusted residual trait values, and Cox survival models to test incident diabetes. RESULTS We found 415 SNPs associated (at p < 0.001) with at least one of the six quantitative traits in GEE, 242 in FBAT (18 overlapped with GEE for 639 non-overlapping SNPs), and 128 associated with incident diabetes (31 overlapped with the 639) giving 736 non-overlapping SNPs. Of these 736 SNPs, 439 were within 60 kb of a known gene. Additionally, 53 SNPs (of which 42 had r2 < 0.80 with each other) had p < 0.01 for incident diabetes AND (all 3 glucose traits OR all 3 insulin traits, OR 2 glucose traits and 2 insulin traits); of these, 36 overlapped with the 736 other SNPs. Of 100K SNPs, one (rs7100927) was in moderate LD (r2 = 0.50) with TCF7L2 (rs7903146), and was associated with risk of diabetes (Cox p-value 0.007, additive hazard ratio for diabetes = 1.56) and with tFPG (GEE p-value 0.03). There were no common (MAF > 1%) 100K SNPs in LD (r2 > 0.05) with ABCC8 A1369S (rs757110), KCNJ11 E23K (rs5219), or SNPs in CAPN10 or HNFa. PPARG P12A (rs1801282) was not significantly associated with diabetes or related traits. CONCLUSION Framingham 100K SNP data is a resource for association tests of known and novel genes with diabetes and related traits posted at http://www.ncbi.nlm.nih.gov/projects/gap/cgi-bin/study.cgi?id=phs000007 webcite. Framingham 100K data replicate the TCF7L2 association with diabetes.
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Affiliation(s)
- James B Meigs
- General Medicine Division, Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Alisa K Manning
- Department of Biostatistics, Boston University School of Public Health, Boston, MA, USA
| | - Caroline S Fox
- The Division of Endocrinology, Diabetes, and Hypertension, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, and the National Heart, Lung, and Blood Institute's Framingham Heart Study, Framingham, MA, USA
| | - Jose C Florez
- Diabetes Unit, Department of Medicine and Center for Human Genetic Research, Massachusetts General Hospital and Harvard Medical School, Boston, MA, and Program in Medical and Population Genetics, Broad Institute of Harvard and MIT, Cambridge, MA, USA
| | - Chunyu Liu
- Department of Biostatistics, Boston University School of Public Health, Boston, MA, USA
| | - L Adrienne Cupples
- Department of Biostatistics, Boston University School of Public Health, Boston, MA, USA
| | - Josée Dupuis
- Department of Biostatistics, Boston University School of Public Health, Boston, MA, USA
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Abstract
BACKGROUND TCF7L2 belongs to a subfamily of TCF7-like HMG box-containing transcription factors, and maps to human chromosome 10q25.3. A recent study identified genetic association of type 2 diabetes (T2D) with this gene, correlated with diminished insulin secretion. This study aimed to investigate the possibility of genetic association between TCF7L2 and type 1 diabetes (T1D). METHODS The SNP most significantly associated with T2D, rs7903146, was genotyped in 886 T1D nuclear family trios with ethnic backgrounds of mixed European descent. RESULTS This study found no T1D association with, and no age-of-onset effect from rs7903146. CONCLUSION This study suggests that a T2D mechanism mediated by TCF7L2 does not participate in the etiology of T1D.
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Bibliography. Current world literature. Diabetes and the endocrine pancreas II. Curr Opin Endocrinol Diabetes Obes 2007; 14:329-57. [PMID: 17940461 DOI: 10.1097/MED.0b013e3282c3a898] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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