A genome screen for linkage disequilibrium in Turkish multiple sclerosis

A genome screen for linkage disequilibrium in Turkish multiple sclerosisM. Eraksoya,*,1, A. Hensiekb,1, M. Kurtuncua,b, G. Akman-Demira, M. Kılıncc,M. Gedizlioglud, B. Petek-Balcıe, O¨ . Anlarf, C. Kutlug, G. Saruhan-Direskenelih,H.A. I˙drisoglua, E. Setakisi, A. Compstonb, S. SawcerbThe Turkish Multiple Sclerosis Genetics Study Group (TMSGSG)a Department of Neurology, Istanbul Faculty of Medicine, University of Istanbul, Capa, Istanbul TR-34390, Turkeyb Neurology Unit, Addenbrooke’s Hospital, University of Cambridge, Cambridge CB2 2QQ, UKc Department of Neurology, Faculty of Medicine, University of Baskent, Ankara, Turkeyd Department of Neurology, Buca Social Security Hospital, I˙zmir, Turkeye Department of Neurology, Haseki State Hospital, Istanbul, Turkeyf Department of Neurology, Faculty of Medicine, University of Yu¨zu¨ncu¨ yıl, Van, Turkeyg Department of Neurology, Faculty of Medicine, University of Osmangazi, Eskisehir, Turkeyh Neuroimmunology Laboratory, Department of Physiology, Istanbul Faculty of Medicine, University of Istanbul, Istanbul, TurkeyiMRC Biostatistics Unit, Institute of Public Health, University Forvie Site, Cambridge, UKAbstractIn order to screen the Turkish population for evidence of association with multiple sclerosis, we typed 6000 microsatellite markers inseparately pooled DNA samples from 197 cases and 199 controls following the Genetic Analysis of Multiple sclerosis in EuropeanS(GAMES) protocol. Twelve markers showing evidence for association were identified. One of these markers lying directly in a region whichis also implicated in the Turkish linkage screen (chromosome 5p15) and thus shows evidence for both linkage and association in independentdata sets.D 2003 Elsevier B.V. All rights reserved.Keywords: Multiple sclerosis; Turkey; Linkage disequilibrium; Genome screen1. IntroductionAvailable epidemiological evidence indicates that severalgenes determine susceptibility to multiple sclerosis witheach contributing only modest effect individually (Compston,2000). In this complex situation, tests for associationare significantly more powerful than those based on linkageand a genome-wide effort to find association by testing allpossible variants systematically would be the ideal experiment(Collins et al., 1997; Risch and Merikangas, 1996).Direct screenin