title: Fragile X-associated tremor ataxia syndrome in FMR1 gray zone allele carriers.
abstract: BACKGROUND
  Carriers of fragile X mental retardation 1 (FMR1) repeat expansions in the premutation range (55-200 CGG repeats) often develop a syndrome of kinetic tremor, cerebellar ataxia, and parkinsonism; designated the fragile X-associated tremor ataxia syndrome (FXTAS). Neurological signs have not been reported in carriers of gray zone (45-54 CGG repeats) expansions.
  
  
  RESULTS
  We describe 3 patients with FMR1 gray zone alleles who meet diagnostic criteria for FXTAS.
  
  
  CONCLUSIONS
  Our cases suggest that the definition of the FXTAS may need to be broadened to include individuals with FMR1 repeat expansions in the gray zone. These neurological signs may be due to elevated levels of expanded CGG repeat FMR1 mRNA in the gray zone carriers, similar to the changes seen in premutation carriers with FXTAS.
authors.affiliation: Department of Neurological Sciences, Rush University, Chicago, Illinois, USA. Deborah.Hall@ucdenver.edu
authors.forename: Deborah
authors.initials: D
authors.lastname: Hall
authors.forename: Flora
authors.initials: F
authors.lastname: Tassone
authors.forename: Olga
authors.initials: O
authors.lastname: Klepitskaya
authors.forename: Maureen
authors.initials: M
authors.lastname: Leehey
mesh_terms: D000368:Aged; D001259:Ataxia / Q000209:etiology* / Q000235:genetics; D005260:Female; D051860:Fragile X Messenger Ribonucleoprotein 1 / Q000235:genetics*; D005600:Fragile X Syndrome / Q000150:complications* / Q000235:genetics*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D014202:Tremor / Q000209:etiology* / Q000235:genetics; D018911:Trinucleotide Repeats / Q000235:genetics*
chemical_list: D051860:Fragile X Messenger Ribonucleoprotein 1