title: Linkage disequilibrium between the MBP tetranucleotide repeat and multiple sclerosis is restricted to a geographically defined subpopulation in Finland.
abstract: We have previously found evidence for linkage as well as allelic and haplotype association between the myelin basic protein (MBP) gene and multiple sclerosis (MS). These findings have, however, not been reproduced in other populations. Here, we have analyzed association between MBP and MS in a new set of 349 Finnish triad families. Families with a parent born in the Southern Ostrobothnian region in western Finland (Bothnia families, n=98) were analyzed as a separate group since our previous studies included a high proportion of patients and families from this high-incidence region. Other families (n=251) were collected at five hospitals in southern, eastern, and northern Finland. The MBP short tandem repeat was genotyped, and haplotype patterns were verified by sequencing. In the Bothnia families, the previously detected associations with the 1.27 kb allele and haplotype 1.27-B10 were confirmed (P=0.01 and 0.02, respectively), whereas in the other families there was not even a trend toward association. These results demonstrate a geographic/genealogical restriction in the association between MS and the MBP short tandem repeat, highlight the importance of genealogical information in genetic studies of complex traits, and may provide an explanation why the association has not been found in many other populations.
authors.affiliation: Department of Neurolofy, University of Helsinki and Helsinki University Hospital, Helsinki, Finland.
authors.forename: H
authors.initials: H
authors.lastname: Pihlaja
authors.forename: T
authors.initials: T
authors.lastname: Rantamäki
authors.forename: J
authors.initials: J
authors.lastname: Wikström
authors.forename: M-L
authors.initials: ML
authors.lastname: Sumelahti
authors.forename: M
authors.initials: M
authors.lastname: Laaksonen
authors.forename: J
authors.initials: J
authors.lastname: Ilonen
authors.forename: J
authors.initials: J
authors.lastname: Ruutiainen
authors.forename: T
authors.initials: T
authors.lastname: Pirttilä
authors.forename: I
authors.initials: I
authors.lastname: Elovaara
authors.forename: M
authors.initials: M
authors.lastname: Reunanen
authors.forename: S
authors.initials: S
authors.lastname: Kuokkanen
authors.forename: L
authors.initials: L
authors.lastname: Peltonen
authors.forename: K
authors.initials: K
authors.lastname: Koivisto
authors.forename: P J
authors.initials: PJ
authors.lastname: Tienari
mesh_terms: D000483:Alleles; D001483:Base Sequence; D005191:Family Characteristics; D005260:Female; D005387:Finland / Q000453:epidemiology; D020022:Genetic Predisposition to Disease; D006239:Haplotypes; D006801:Humans; D015810:Linkage Disequilibrium; D008297:Male; D018895:Microsatellite Repeats; D009103:Multiple Sclerosis / Q000453:epidemiology / Q000235:genetics*; D004676:Myelin Basic Protein / Q000235:genetics*; D009679:Nuclear Family; D020080:Tandem Repeat Sequences
chemical_list: D004676:Myelin Basic Protein