title: FMR1 gray-zone alleles: association with Parkinson's disease in women?
abstract: Carriers of fragile X mental retardation 1 repeat expansions in the premutation range (55-200 CGG repeats), especially males, often develop tremor, ataxia, and parkinsonism. These neurological signs are believed to be a result of elevated levels of expanded CGG-repeat fragile X mental retardation 1 mRNA. The purpose of this study was to determine the prevalence of fragile X mental retardation 1 repeat expansions in a movement disorder population comprising subjects with all types of tremor, ataxia, and parkinsonism. We screened 335 consecutive patients with tremor, ataxia, or parkinsonism and 273 controls confirmed to have no movement disorders. There was no difference in fragile X mental retardation 1 premutation size expansions in the cases compared with controls. Eleven percent of the women with Parkinson's disease had fragile X mental retardation 1 gray-zone expansions compared with 4.4% of female controls (odds ratio of 3.2; 95% confidence interval, 1.2-8.7). Gray-zone expansions in patients with other phenotypes were not overrepresented in comparison with controls. Fragile X mental retardation 1 premutation range expansions are not more common in a mixed movement disorder population compared with controls. Our results, however, suggest that fragile X mental retardation 1 gray-zone alleles may be associated with Parkinson's disease in women.
authors.affiliation: Department of Neurological Sciences, Rush University, 1725 West Harrison St., Suite 755, Chicago, IL 60611, USA. Deborah_A_Hall@rush.edu
authors.forename: Deborah A
authors.initials: DA
authors.lastname: Hall
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Berry-Kravis
authors.forename: Wenting
authors.initials: W
authors.lastname: Zhang
authors.forename: Flora
authors.initials: F
authors.lastname: Tassone
authors.forename: Elaine
authors.initials: E
authors.lastname: Spector
authors.forename: Gary
authors.initials: G
authors.lastname: Zerbe
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Hagerman
authors.forename: Bichun
authors.initials: B
authors.lastname: Ouyang
authors.forename: Maureen A
authors.initials: MA
authors.lastname: Leehey
mesh_terms: D000328:Adult; D000368:Aged; D000483:Alleles; D005260:Female; D051860:Fragile X Messenger Ribonucleoprotein 1 / Q000235:genetics*; D020022:Genetic Predisposition to Disease; D005820:Genetic Testing; D006801:Humans; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D010300:Parkinson Disease / Q000453:epidemiology / Q000235:genetics*; D012189:Retrospective Studies; D012737:Sex Factors; D019680:Trinucleotide Repeat Expansion / Q000235:genetics*
chemical_list: D051860:Fragile X Messenger Ribonucleoprotein 1; C497683:FMR1 protein, human