Open Access Research article

Gene expression profiles in Finnish twins with multiple sclerosis

Silja Särkijärvi1, Hanna Kuusisto2, Raija Paalavuo1, Mari Levula3, Nina Airla3, Terho Lehtimäki3, Jaakko Kaprio45, Markku Koskenvuo4 and Irina Elovaara12*

Author Affiliations

1 Neuroimmunology Unit, Department of Neurology, Tampere University Hospital, Teiskontie, 35, 33520 Tampere, Finland

2 Department of Neurology, Tampere University Hospital, Teiskontie 35, 33520 Tampere, Finland

3 Laboratory of Atherosclerosis Genetics, Department of Clinical Chemistry, Center for Laboratory Medicine, Tampere University Hospital, and Medical School, University of Tampere, Teiskontie 35, 33520 Tampere, Finland

4 Department of Public Health, P.O. Box 41, University of Helsinki, FIN-00014 Helsinki, Finland

5 Department of Mental Health and Alcohol Research, National Public Health Institute, Mannerheimintie 166, FIN-00300 Helsinki, Finland

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BMC Medical Genetics 2006, 7:11  doi:10.1186/1471-2350-7-11

Published: 27 February 2006



Since genetic alterations influencing susceptibility to multiple sclerosis (MS), the most common autoimmune demyelinating disease of the central nervous system (CNS), are as yet poorly understood, the purpose of this study was to identify genes responsible for MS by studying monozygotic (MZ) twin pairs discordant for MS.


In order to identify genes involved in MS development, the gene expression profiles in blood mononuclear cells obtained from eight MZ twin pairs discordant for MS were analyzed by cDNA microarray technology detecting the expression of 8 300 genes. The twins were collected from the Finnish Twin Cohort Study and both affected subjects and their healthy siblings underwent neurological evaluation and cerebral and spinal magnetic resonance imaging. Gene expressions were confirmed by relative quantitative reverse transcription PCR.


It appeared that 25 genes were at least two-fold up-regulated and 15 genes down-regulated in 25% (2/8) of twins with MS when compared to their healthy siblings. Moreover, 6/25 genes were up-regulated in 40% of MS twins and one gene, interferon alpha-inducible protein (clone IFI-6-16) (G1P3), in 50% of them. The six most constantly expressed genes are (1) G1P3, (2) POU domain, class 3, transcription factor 1, (3) myxovirus resistance 2, (4) lysosomal-associated multispanning membrane protein-5, (5) hemoglobin alpha 2 and (6) hemoglobin beta.


Over two-fold up-regulation of these six genes in almost half of MZ twins with MS suggests their role in MS pathogenesis. Studies using MZ MS twins obtained from genetically homogeneous population offer a unique opportunity to explore the genetic nature of MS.