Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • Review Article
  • Published:

From genes to function: the next challenge to understanding multiple sclerosis

Key Points

  • The availability of genetic determinants of multiple sclerosis that have emerged from recent genome-wide association studies creates opportunities to explain for the first time the biological factors that are responsible for the pathophysiology of this disease. These associations implicate genes that fall into two broad categories, immunological genes and neurological genes.

  • Much more work is needed to confirm the disease-associated genetic variants that are responsible for these associations and to attribute this risk to individual loci. In addition, other sorts of genetic variation that have not yet been systematically evaluated in multiple sclerosis, such as rare variants, private mutations and copy number variations, could contribute further to our understanding of heritability.

  • The ultimate proof of causality for a genetic variant will require functional data. This may be partly provided by expression analysis or simple cellular assays but may also require new approaches and animal models that allow exploration of pathway variations using multiple variants or that alter the activity of pathways implicated in disease in humans.

  • Environmental factors will remain crucial to our understanding of disease risk and pathogenesis. These may be easier to identify if genetics analysis provides clues as to what they may be or if epigenetic modification can be detected that indicates how environmental factors and genes may interact.

  • Other tools, such as experimental medicine in genotyped individuals to detect the biological effects of these polymorphisms as well as modelling and simulation, will also be crucial approaches to dissecting functional roles of these new variants.

Abstract

Susceptibility to multiple sclerosis is jointly determined by genetic and environmental factors, and progress has been made in defining some of these genetic associations, as well as their possible interactions with the environment. However, definitive proof for the involvement of specific genetic determinants in the disease will only come from studies that examine their functional roles in disease pathogenesis. New and combined approaches are needed to analyse the complexity of gene regulation and the functional contribution of each genetic determinant to disease susceptibility or pathophysiology. These studies should proceed in parallel with the use of genetically defined human populations to explore how both genetic and environmental factors affect the function of the pathways in individuals with and without disease, and how these determine the inherited risk of multiple sclerosis.

This is a preview of subscription content, access via your institution

Access options

Buy this article

Prices may be subject to local taxes which are calculated during checkout

Figure 1: The HLA-DR2a molecule modifies multiple sclerosis-like disease mediated by the HLA-DR2b molecule by functional epistasis.
Figure 2: Opposing effects of HLA class I molecules on autoreactive CD8+ T cells in a mouse model of multiple sclerosis.

Similar content being viewed by others

References

  1. Sospedra, M. & Martin, R. Immunology of multiple sclerosis. Annu. Rev. Immunol. 23, 683–747 (2005).

    Article  CAS  PubMed  Google Scholar 

  2. Lopez-Diego, R. S. & Weiner, H. L. Novel therapeutic strategies for multiple sclerosis — a multifaceted adversary. Nature Rev. Drug Discov. 7, 909–925 (2008).

    Article  CAS  Google Scholar 

  3. Correale, J., Fiol, M. & Gilmore, W. The risk of relapses in multiple sclerosis during systemic infections. Neurology 67, 652–659 (2006).

    Article  CAS  PubMed  Google Scholar 

  4. Ascherio, A. & Munger, K. L. Environmental risk factors for multiple sclerosis. Part II: noninfectious factors. Ann. Neurol. 61, 504–513 (2007).

    Article  CAS  PubMed  Google Scholar 

  5. Oksenberg, J. R., Baranzini, S. E., Sawcer, S. & Hauser, S. L. The genetics of multiple sclerosis: SNPs to pathways to pathogenesis. Nature Rev. Genet. 9, 516–526 (2008).

    Article  CAS  PubMed  Google Scholar 

  6. Bertrams, J., Kuwert, E. & Liedtke, U. HL-A antigens and multiple sclerosis. Tissue Antigens 2, 405–408 (1972).

    Article  CAS  PubMed  Google Scholar 

  7. Jersild, C., Svejgaard, A. & Fog, T. HL-A antigens and multiple sclerosis. Lancet 1, 1240–1241 (1972).

    Article  CAS  PubMed  Google Scholar 

  8. Naito, S., Namerow, N., Mickey, M. R. & Terasaki, P. I. Multiple sclerosis: association with HL-A3. Tissue Antigens 2, 1–4 (1972).

    Article  CAS  PubMed  Google Scholar 

  9. Jersild, C. et al. Histocompatibility determinants in multiple sclerosis, with special reference to clinical course. Lancet 2, 1221–1225 (1973).

    Article  CAS  PubMed  Google Scholar 

  10. Lincoln, M. R. et al. A predominant role for the HLA class II region in the association of the MHC region with multiple sclerosis. Nature Genet. 37, 1108–1112 (2005).

    Article  CAS  PubMed  Google Scholar 

  11. Oksenberg, J. R. et al. Mapping multiple sclerosis susceptibility to the HLA-DR locus in African Americans. Am. J. Hum. Genet. 74, 160–167 (2004).

    Article  CAS  PubMed  Google Scholar 

  12. Barcellos, L. F. et al. Heterogeneity at the HLA-DRB1 locus and risk for multiple sclerosis. Hum. Mol. Genet. 15, 2813–2824 (2006).

    Article  CAS  PubMed  Google Scholar 

  13. Dyment, D. A., Ebers, G. C. & Sadovnick, A. D. Genetics of multiple sclerosis. Lancet Neurol. 3, 104–110 (2004).

    Article  CAS  PubMed  Google Scholar 

  14. Fogdell-Hahn, A., Ligers, A., Gronning, M., Hillert, J. & Olerup, O. Multiple sclerosis: a modifying influence of HLA class I genes in an HLA class II associated autoimmune disease. Tissue Antigens 55, 140–148 (2000).

    Article  CAS  PubMed  Google Scholar 

  15. Harbo, H. F. et al. Genes in the HLA class I region may contribute to the HLA class II-associated genetic susceptibility to multiple sclerosis. Tissue Antigens 63, 237–247 (2004).

    Article  CAS  PubMed  Google Scholar 

  16. Brynedal, B. et al. HLA-A confers an HLA-DRB1 independent influence on the risk of multiple sclerosis. PLoS ONE 2, e664 (2007).

    Article  PubMed  PubMed Central  CAS  Google Scholar 

  17. Yeo, T. W. et al. A second major histocompatibility complex susceptibility locus for multiple sclerosis. Ann. Neurol. 61, 228–236 (2007).

    Article  PubMed  PubMed Central  CAS  Google Scholar 

  18. Hafler, D. A. et al. Risk alleles for multiple sclerosis identified by a genome-wide study. N. Engl. J. Med. 357, 851–862 (2007). This study shows that multiple sclerosis is associated with several genetic variants in or around immunologically relevant genes. The MHC region confers the largest risk, whereas the contributions from other risk genes, such as IL7R and IL2R , are small by comparison.

    Article  CAS  PubMed  Google Scholar 

  19. Lundmark, F. et al. Variation in interleukin 7 receptor α chain (IL7R) influences risk of multiple sclerosis. Nature Genet. 39, 1108–1113 (2007).

    Article  CAS  PubMed  Google Scholar 

  20. Ban, M. et al. Replication analysis identifies TYK2 as a multiple sclerosis susceptibility factor. Eur. J. Hum. Genet. 18 Mar 2009 (doi:10.1038/ejhg.2009.41).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  21. Reich, D. et al. A whole-genome admixture scan finds a candidate locus for multiple sclerosis susceptibility. Nature Genet. 37, 1113–1118 (2005).

    Article  CAS  PubMed  Google Scholar 

  22. Hafler, J. P. et al. CD226 Gly307Ser association with multiple autoimmune diseases. Genes Immun. 10, 305–310 (2009).

    Article  CAS  Google Scholar 

  23. Bernardinelli, L. et al. Association between the ACCN1 gene and multiple sclerosis in central east Sardinia. PLoS ONE 2, e480 (2007).

    Article  PubMed  PubMed Central  CAS  Google Scholar 

  24. Aulchenko, Y. S. et al. Genetic variation in the KIF1B locus influences susceptibility to multiple sclerosis. Nature Genet. 40, 1402–1403 (2008).

    Article  CAS  PubMed  Google Scholar 

  25. Wemmie, J. A., Price, M. P. & Welsh, M. J. Acid-sensing ion channels: advances, questions and therapeutic opportunities. Trends Neurosci. 29, 578–586 (2006).

    Article  CAS  PubMed  Google Scholar 

  26. Boldogh, I. R. & Pon, L. A. Mitochondria on the move. Trends Cell Biol. 17, 502–510 (2007).

    Article  CAS  PubMed  Google Scholar 

  27. Nangaku, M. et al. KIF1B, a novel microtubule plus end-directed monomeric motor protein for transport of mitochondria. Cell 79, 1209–1220 (1994).

    Article  CAS  PubMed  Google Scholar 

  28. Donnelly, P. Progress and challenges in genome-wide association studies in humans. Nature 456, 728–731 (2008).

    Article  CAS  PubMed  Google Scholar 

  29. Vavouri, T., McEwen, G. K., Woolfe, A., Gilks, W. R. & Elgar, G. Defining a genomic radius for long-range enhancer action: duplicated conserved non-coding elements hold the key. Trends Genet. 22, 5–10 (2006).

    Article  CAS  PubMed  Google Scholar 

  30. Feuk, L., Carson, A. R. & Scherer, S. W. Structural variation in the human genome. Nature Rev. Genet. 7, 85–97 (2006).

    Article  CAS  PubMed  Google Scholar 

  31. Nejentsev, S., Walker, N., Riches, D., Egholm, M. & Todd, J. A. Rare variants of IFIH1, a gene implicated in antiviral responses, protect against type 1 diabetes. Science 5 Mar 2009 (doi:10.1126/science.1167728). This paper shows that re-sequencing studies can pinpoint disease-causing genes in genomic regions initially identified by genome-wide association studies.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  32. Madsen, L. S. et al. A humanized model for multiple sclerosis using HLA-DR2 and a human T-cell receptor. Nature Genet. 23, 343–347 (1999).

    Article  CAS  PubMed  Google Scholar 

  33. Molberg, O. et al. Tissue transglutaminase selectively modifies gliadin peptides that are recognized by gut-derived T cells in celiac disease. Nature Med. 4, 713–717 (1998).

    Article  CAS  PubMed  Google Scholar 

  34. Cookson, W., Liang, L., Abecasis, G., Moffatt, M. & Lathrop, M. Mapping complex disease traits with global gene expression. Nature Rev. Genet. 10, 184–194 (2009).

    Article  CAS  PubMed  Google Scholar 

  35. Chen, Y. et al. Variations in DNA elucidate molecular networks that cause disease. Nature 452, 429–435 (2008).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  36. Emilsson, V. et al. Genetics of gene expression and its effect on disease. Nature 452, 423–428 (2008). This study assesses the relationship between DNA sequence variants and gene expression. For a recent review on this subject see reference 34.

    Article  CAS  PubMed  Google Scholar 

  37. Goring, H. H. et al. Discovery of expression QTLs using large-scale transcriptional profiling in human lymphocytes. Nature Genet. 39, 1208–1216 (2007).

    Article  PubMed  CAS  Google Scholar 

  38. Moffatt, M. F. et al. Genetic variants regulating ORMDL3 expression contribute to the risk of childhood asthma. Nature 448, 470–473 (2007).

    Article  CAS  PubMed  Google Scholar 

  39. Maier, L. M. et al. Soluble IL-2RA levels in multiple sclerosis subjects and the effect of soluble IL-2RA on immune responses. J. Immunol. 182, 1541–1547 (2009).

    Article  CAS  PubMed  Google Scholar 

  40. Maier, L. M. et al. IL2RA genetic heterogeneity in multiple sclerosis and type 1 diabetes susceptibility and soluble interleukin-2 receptor production. PLoS Genet. 5, e1000322 (2009).

    Article  PubMed  PubMed Central  CAS  Google Scholar 

  41. De Jager, P. L. et al. The role of the CD58 locus in multiple sclerosis. Proc. Natl Acad. Sci. USA 106, 5264–5269 (2009).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  42. Gregory, S. G. et al. Interleukin 7 receptor α chain (IL7R) shows allelic and functional association with multiple sclerosis. Nature Genet. 39, 1083–1091 (2007).

    Article  CAS  PubMed  Google Scholar 

  43. Nunnari, G. et al. Exogenous IL-7 induces Fas-mediated human neuronal apoptosis: potential effects during human immunodeficiency virus type 1 infection. J. Neurovirol. 11, 319–328 (2005).

    Article  CAS  PubMed  Google Scholar 

  44. Park, I. H. et al. Reprogramming of human somatic cells to pluripotency with defined factors. Nature 451, 141–146 (2008).

    Article  CAS  PubMed  Google Scholar 

  45. Takahashi, K. et al. Induction of pluripotent stem cells from adult human fibroblasts by defined factors. Cell 131, 861–872 (2007).

    Article  CAS  PubMed  Google Scholar 

  46. Yu, J. et al. Induced pluripotent stem cell lines derived from human somatic cells. Science 318, 1917–1920 (2007).

    Article  CAS  PubMed  Google Scholar 

  47. Aasen, T. et al. Efficient and rapid generation of induced pluripotent stem cells from human keratinocytes. Nature Biotechnol. 26, 1276–1284 (2008).

    Article  CAS  Google Scholar 

  48. Loh, Y. H. et al. Generation of induced pluripotent stem cells from human blood. Blood 18 Mar 2009 (doi:10.1182/blood-2009-02-204800).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  49. Kaji, K. et al. Virus-free induction of pluripotency and subsequent excision of reprogramming factors. Nature 58, 771–775 (2009).

    Article  CAS  Google Scholar 

  50. Yamanaka, S. A fresh look at iPS cells. Cell 137, 13–17 (2009). This is mandatory reading for those wishing to catch up with the iPS cell field.

    Article  CAS  PubMed  Google Scholar 

  51. Dimos, J. T. et al. Induced pluripotent stem cells generated from patients with ALS can be differentiated into motor neurons. Science 321, 1218–1221 (2008).

    Article  CAS  PubMed  Google Scholar 

  52. Ebert, A. D. et al. Induced pluripotent stem cells from a spinal muscular atrophy patient. Nature 457, 277–280 (2009). This is the first study to show that human iPS cells can be used to model the specific pathology seen in a genetically inherited disease.

    Article  CAS  PubMed  Google Scholar 

  53. Soldner, F. et al. Parkinson's disease patient-derived induced pluripotent stem cells free of viral reprogramming factors. Cell 136, 964–977 (2009).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  54. Borrelli, E., Nestler, E. J., Allis, C. D. & Sassone-Corsi, P. Decoding the epigenetic language of neuronal plasticity. Neuron 60, 961–974 (2008).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  55. Chao, M. J. et al. Epigenetics in multiple sclerosis susceptibility: difference in transgenerational risk localizes to the major histocompatibility complex. Hum. Mol. Genet. 18, 261–266 (2009).

    Article  CAS  PubMed  Google Scholar 

  56. Zhang, X. et al. Genome-wide high-resolution mapping and functional analysis of DNA methylation in arabidopsis. Cell 126, 1189–1201 (2006).

    Article  CAS  PubMed  Google Scholar 

  57. Mockler, T. C. et al. Applications of DNA tiling arrays for whole-genome analysis. Genomics 85, 1–15 (2005).

    Article  CAS  PubMed  Google Scholar 

  58. Shen, S. et al. Age-dependent epigenetic control of differentiation inhibitors is critical for remyelination efficiency. Nature Neurosci. 11, 1024–1034 (2008). References 54 and 58 suggest that investigating dysregulated posttranslational modifications in multiple sclerosis may contribute to our understanding of its pathogenesis.

    Article  CAS  PubMed  Google Scholar 

  59. Friese, M. A. et al. The value of animal models for drug development in multiple sclerosis. Brain 129, 1940–1952 (2006).

    Article  PubMed  Google Scholar 

  60. Steinman, L. Blocking adhesion molecules as therapy for multiple sclerosis: natalizumab. Nature Rev. Drug Discov. 4, 510–518 (2005).

    Article  CAS  Google Scholar 

  61. Gregersen, J. W. et al. Functional epistasis on a common MHC haplotype associated with multiple sclerosis. Nature 443, 574–577 (2006).

    Article  CAS  PubMed  Google Scholar 

  62. Caillier, S. J. et al. Uncoupling the roles of HLA-DRB1 and HLA-DRB5 genes in multiple sclerosis. J. Immunol. 181, 5473–5480 (2008).

    Article  CAS  PubMed  Google Scholar 

  63. Polman, C. H. et al. A randomized, placebo-controlled trial of natalizumab for relapsing multiple sclerosis. N. Engl. J. Med. 354, 899–910 (2006).

    Article  CAS  PubMed  Google Scholar 

  64. Coles, A. J. et al. Alemtuzumab vs. interferon β-1a in early multiple sclerosis. N. Engl. J. Med. 359, 1786–1801 (2008).

    Article  PubMed  Google Scholar 

  65. Friese, M. A. et al. Opposing effects of HLA class I molecules in tuning autoreactive CD8+ T cells in multiple sclerosis. Nature Med. 14, 1227–1235 (2008). This study exemplifies how functional genetics can be used to understand disease-association studies that are directly relevant to multiple sclerosis.

    Article  CAS  PubMed  Google Scholar 

  66. Bell, G. I., Horita, S. & Karam, J. H. A polymorphic locus near the human insulin gene is associated with insulin-dependent diabetes mellitus. Diabetes 33, 176–183 (1984).

    Article  CAS  PubMed  Google Scholar 

  67. Vafiadis, P. et al. Insulin expression in human thymus is modulated by INS VNTR alleles at the IDDM2 locus. Nature Genet. 15, 289–292 (1997).

    Article  CAS  PubMed  Google Scholar 

  68. Pugliese, A. et al. The insulin gene is transcribed in the human thymus and transcription levels correlated with allelic variation at the INS VNTR-IDDM2 susceptibility locus for type 1 diabetes. Nature Genet. 15, 293–297 (1997).

    Article  CAS  PubMed  Google Scholar 

  69. Chentoufi, A. A. & Polychronakos, C. Insulin expression levels in the thymus modulate insulin-specific autoreactive T-cell tolerance: the mechanism by which the IDDM2 locus may predispose to diabetes. Diabetes 51, 1383–1390 (2002).

    Article  CAS  PubMed  Google Scholar 

  70. Lunemann, J. D. et al. EBNA1-specific T cells from patients with multiple sclerosis cross react with myelin antigens and co-produce IFN-γ and IL-2. J. Exp. Med. 205, 1763–1773 (2008).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  71. Harkiolaki, M. et al. T cell-mediated autoimmune disease due to low-affinity crossreactivity to common microbial peptides. Immunity 30, 348–357 (2009).

    Article  CAS  PubMed  Google Scholar 

  72. Oldstone, M. B. Molecular mimicry and autoimmune disease. Cell 50, 819–820 (1987).

    Article  CAS  PubMed  Google Scholar 

  73. Quintana, F. J. et al. Control of Treg and TH17 cell differentiation by the aryl hydrocarbon receptor. Nature 453, 65–71 (2008).

    Article  CAS  PubMed  Google Scholar 

  74. Veldhoen, M. et al. The aryl hydrocarbon receptor links TH17-cell-mediated autoimmunity to environmental toxins. Nature 453, 106–109 (2008). References 73 and 74 show the role of the environmental toxin dioxin in affecting T Reg and T H 17 cell activation and provide a potentially useful clue about the possible role of environmental triggers in disease initiation.

    Article  CAS  PubMed  Google Scholar 

  75. Bettelli, E., Korn, T., Oukka, M. & Kuchroo, V. K. Induction and effector functions of T H17 cells. Nature 453, 1051–1057 (2008).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  76. Tzartos, J. S. et al. Interleukin-17 production in central nervous system-infiltrating T cells and glial cells is associated with active disease in multiple sclerosis. Am. J. Pathol. 172, 146–155 (2008).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  77. Ramagopalan, S. V. et al. Expression of the multiple sclerosis-associated MHC class II allele HLA-DRB1*1501 is regulated by vitamin D. PLoS Genet. 5, e1000369 (2009).

    Article  PubMed  PubMed Central  CAS  Google Scholar 

  78. Friese, M. A. et al. Acid-sensing ion channel-1 contributes to axonal degeneration in autoimmune inflammation of the central nervous system. Nature Med. 13, 1483–1489 (2007).

    Article  CAS  PubMed  Google Scholar 

  79. Gimeno, R. et al. Monitoring the effect of gene silencing by RNA interference in human CD34+ cells injected into newborn RAG2−/− γc−/− mice: functional inactivation of p53 in developing T cells. Blood 104, 3886–3893 (2004).

    Article  CAS  PubMed  Google Scholar 

  80. Traggiai, E. et al. Development of a human adaptive immune system in cord blood cell-transplanted mice. Science 304, 104–107 (2004).

    Article  CAS  PubMed  Google Scholar 

  81. Shultz, L. D., Ishikawa, F. & Greiner, D. L. Humanized mice in translational biomedical research. Nature Rev. Immunol. 7, 118–130 (2007).

    Article  CAS  Google Scholar 

  82. Baranzini, S. E. et al. Pathway and network-based analysis of genome-wide association studies in multiple sclerosis. Hum. Mol. Genet. 13 Mar 2009 (doi:10.1093/hmg/ddp120).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  83. Baranzini, S. E. et al. Genome-wide association analysis of susceptibility and clinical phenotype in multiple sclerosis. Hum. Mol. Genet. 18, 767–778 (2009).

    Article  CAS  PubMed  Google Scholar 

  84. McFarland, H. F. & Martin, R. Multiple sclerosis: a complicated picture of autoimmunity. Nature Immunol. 8, 913–919 (2007).

    Article  CAS  Google Scholar 

  85. Frischer, J. M. et al. The relation between inflammation and neurodegeneration in multiple sclerosis brains. Brain 31 Mar 2009 (doi:10.1093/brain/awp070).

    Article  PubMed  PubMed Central  Google Scholar 

  86. Frohman, E. M., Racke, M. K. & Raine, C. S. Multiple sclerosis — the plaque and its pathogenesis. N. Engl. J. Med. 354, 942–955 (2006).

    Article  CAS  PubMed  Google Scholar 

  87. Goodnow, C. C. Multistep pathogenesis of autoimmune disease. Cell 130, 25–35 (2007).

    Article  CAS  PubMed  Google Scholar 

Download references

Acknowledgements

We thank N. Willcox and A. Vincent for critical reading of the manuscript. Work in the authors' laboratories is supported by the Danish and UK Medical Research Councils, the Karen Elise Jensen Foundation, the Lundbeck Foundation, the Danish Multiple Sclerosis Society, the European Union (European Commission Descartes Prize, FP6 (Neuropromise, Mugen and ARDIS) and FP7 (SYBILLA)). M.A.F. is supported by the DFG Emmy Noether Programme (grant number FR1720/3-1).

Author information

Authors and Affiliations

Authors

Corresponding authors

Correspondence to Lars Fugger or John I. Bell.

Related links

Related links

OMIM

amyotrophic lateral sclerosis

spinal muscular atrophy

Parkinson's disease

FURTHER INFORMATION

Lars Fugger's homepage

1000 genomes website

Glossary

Demyelination

Damage to the myelin sheath surrounding nerves in the brain and spinal cord, which affects the function of the nerves involved.

Axonal degeneration

Loss of nerve fibres in response to local damage.

Genome-wide association study

A study designed to look for association between disease and a dense set of markers covering the entire genome.

Linkage disequilibrium

A situation in which alleles in a chromosomal region occur together more often than can be accounted for by chance, indicating that the alleles are in close proximity on the DNA strand and are most likely to be passed on together within a population.

Candidate gene association study

A study that compares the allele frequency of a gene for which there is evidence, usually functional, for a possible role in a disease or trait of interest in cases and controls to assess the contribution of genetic variants to phenotypes in specific populations.

HLA-DR2 haplotype

A combination of alleles at many linked loci that are inherited together; in this case the MHC class II alleles HLA-DRB1*1501 and HLA-DRB5*0101.

Single nucleotide polymorphism

(SNP). Genomic variant in which a single base in the DNA differs from the usual base at that position. SNPs are the most common type of variation in the human genome.

Private variant

The specific genetic variant that only occurs in one individual or family that functionally gives rise to an increased risk conferred by the causal gene or genomic region.

Next generation sequencing technology

Technology that allows for parallel sequencing of massive amounts of DNA. This technology can be used for deep sequencing to sequence whole genomes, transcriptome analysis and for the identification of rare mutants.

eQTL mapping

Combination of quantitative trait loci (regions of DNA that are closely linked to a phenotypic outcome) mapping and gene-expression analysis to study the genetic basis of gene expression and, by extension, biological regulation.

Regulatory T cell

(TReg cell). A type of CD4+ T cell that is characterized by its expression of forkhead box P3 and high levels of CD25. TReg cells can downmodulate many types of immune response.

Induced pluripotent stem cell

A type of pluripotent stem cell that is artificially derived from a non-pluripotent cell, typically an adult somatic cell, by retroviral transfer of a panel of developmentally regulated genes. They can differentiate into multiple cell lineages.

Epigenome

The chromatin states that are found along the whole genome, defined for a given time point and cell type.

Epistatic interaction

Any non-additive interaction between two or more variants at different loci, such that their combined effect on a phenotype differs from the one that would be produced if the two genes were acting independently.

T helper 17

A subset of CD4+ T helper cells that produce interleukin-17 (IL-17) and that are thought to be important in inflammatory and autoimmune diseases. Their generation involves transforming growth factor-β, IL-6, IL-23 or IL-21, IL-1 and the transcription factors RORγt and STAT3.

Tissue acidosis

Lowered pH (acidosis) that is caused by increased glycolysis, production of lactic acid and decreased extracellular and intracellular pH. Tissue acidosis is associated with imbalance between energy supply and demand.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Fugger, L., Friese, M. & Bell, J. From genes to function: the next challenge to understanding multiple sclerosis. Nat Rev Immunol 9, 408–417 (2009). https://doi.org/10.1038/nri2554

Download citation

  • Issue Date:

  • DOI: https://doi.org/10.1038/nri2554

This article is cited by

Search

Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing