The CTLA4 region as a general autoimmunity factor: An extended pedigree provides evidence for synergy with the HLA locus in the etiology of type 1 diabetes mellitus, Hashimoto's thyroiditis and Graves' disease

• Published in: European journal of human genetics : EJHG Vol. 11; no. 1; pp. 81 - 84
• Main Authors: EINARSDOTTIR, Elisabet, SÖDERSTRÖM, Ingegerd, HOLMBERG, Dan, LÖFGREN-BURSTRÖM, Anna, HARALDSSON, Susann, NILSSON-ARDNOR, Sofie, PENHA-GONCALVES, Carlos, LIND, Lisbet, HOLMGREN, Gösta, HOLMBERG, Monica, ASPLUND, Kjell
• Format: Journal Article
• Language: English
• Published: Avenel, NJ Nature Publishing 01.01.2003; Nature Publishing Group
• Subjects: Abatacept; Antigens, CD; Antigens, Differentiation - genetics; Antigens, Differentiation, T-Lymphocyte - genetics; Artificial chromosomes; Autoimmune diseases; autoimmune thyroid disease; Autoimmunity - genetics; Biological and medical sciences; CD28 Antigens - genetics; CTLA-4 Antigen; CTLA-4 protein; CTLA4; Diabetes; Diabetes mellitus; Diabetes mellitus (insulin dependent); Diabetes Mellitus, Type 1 - etiology; Diabetes Mellitus, Type 1 - genetics; Diabetes. Impaired glucose tolerance; DQA1 protein; Endocrine pancreas. Apud cells (diseases); Endocrinopathies; Etiology; Etiopathogenesis. Screening. Investigations. Target tissue resistance; Genetic analysis; Genetic Linkage; Genetic Markers; Genetics; Genomes; Graves Disease - etiology; Graves Disease - genetics; Graves' disease; Haplotypes; Haplotypes - genetics; Hashimoto's thyroiditis; Histocompatibility antigen HLA; HLA; HLA Antigens - genetics; HLA Antigens - immunology; Humans; Immunoconjugates; Inducible T-Cell Co-Stimulator Protein; Insulin; linkage; Lod Score; Medical sciences; Mutation; Pedigree; Studies; Sweden; Thyroid diseases; Thyroiditis; Thyroiditis, Autoimmune - etiology; Thyroiditis, Autoimmune - genetics; type 1 diabetes mellitus; Sweden; Endocrinopathy; Human; Immunopathology; HLA-System; Family study; Pathogenesis; Hyperthyroidism; Thyroid diseases; Autoimmune disease; Genetic determinism; Genetic disease; Phenotype; Hashimoto thyroiditis; Graves disease; Insulin dependent diabetes
• ISSN: 1018-4813; 1476-5438; 1476-5438
• DOI: 10.1038/sj.ejhg.5200903

We have identified a large family in the northern part of Sweden with multiple cases of autoimmune diseases, namely type 1 diabetes (T1D), Graves' disease (GD) and Hashimoto's thyroiditis (HT). The family members affected by any of these diseases share a region of 2.4 Mb that comprises among others the CTLA4 gene. We determined that all affected members of the family shared the HLA susceptibility haplotype (DR4-DQA1*0301-DQB1*0302). Analysis of genetic interaction conditioning for HLA haplotype provided strong evidence that the critical region which includes the CTLA4 gene acts together with the HLA locus on the etiology of disease (lodscore 4.20 (theta=0.0). The study of this family allowed us to: (1) reinforce a number of reports on linkage and association of the CTLA4 region to T1D and AITD; (2) demonstrate that a single haplotypic variant in this region constitutes an etiological factor to disease susceptibility in T1D, GD and HT; (3) reveal a strong genetic interaction of the CTLA4 and HLA loci in the genetic architecture of autoimmune disease; (4) emphasise the value of large pedigrees drawn from isolated populations as tools to single out the effect of individual loci in the etiology of complex diseases.