title: Fragile X premutation with atypical symptoms at onset.
abstract: OBJECTIVE
  To evaluate the presence of carriers of the fragile X premutation among male patients with sporadic ataxia without expansion into known spinocerebellar ataxia genes.
  
  
  METHODS
  Clinical and genetic examinations were performed on patients with sporadic pure ataxia and patients with ataxia associated with extracerebellar features such as pyramidal and extrapyramidal signs, dementia, or peripheral neuropathy.
  
  
  METHODS
  University department of neurology.
  
  
  METHODS
  One hundred forty-two Italian men with sporadic ataxia with onset at age 30 to 84 years.
  
  
  METHODS
  The CGG repeat size of the FMR1 gene was evaluated with fluorescent polymerase chain reaction. Premutated allele lengths were confirmed with Southern blot analysis.
  
  
  RESULTS
  FMR1 premutation alleles with a repeat number greater than 55 were detected in 3 probands (2.1%) from a total of 142 male subjects initially referred to our university medical center for evaluation of sporadic ataxia. Two patients had typical fragile X syndrome with associated tremor or ataxia, and the third patient had spastic paraparesis without clear symptoms of cerebellar ataxia and without the common signs seen at magnetic resonance imaging.
  
  
  CONCLUSIONS
  Genetic analysis of the FMR1 gene could provide a reliable diagnostic tool for the definitive diagnosis of late-onset ataxias. Additional studies are needed to clarify the importance of premutation screening in patients with movement disorders or other associated atypical features at onset, such as paraparesis.
authors.affiliation: Department of Neurological and Psychiatric Sciences, University of Florence, Viale Pieraccini 6, 50139 Florence, Italy. elena.cellini@unifi.it
authors.forename: Elena
authors.initials: E
authors.lastname: Cellini
authors.forename: Paolo
authors.initials: P
authors.lastname: Forleo
authors.forename: Andrea
authors.initials: A
authors.lastname: Ginestroni
authors.forename: Benedetta
authors.initials: B
authors.lastname: Nacmias
authors.forename: Andrea
authors.initials: A
authors.lastname: Tedde
authors.forename: Silvia
authors.initials: S
authors.lastname: Bagnoli
authors.forename: Mario
authors.initials: M
authors.lastname: Mascalchi
authors.forename: Sandro
authors.initials: S
authors.lastname: Sorbi
authors.forename: Silvia
authors.initials: S
authors.lastname: Piacentini
mesh_terms: D000328:Adult; D017668:Age of Onset; D000368:Aged; D000369:Aged, 80 and over; D051860:Fragile X Messenger Ribonucleoprotein 1 / Q000235:genetics*; D005600:Fragile X Syndrome / Q000453:epidemiology* / Q000235:genetics*; D005820:Genetic Testing; D006801:Humans; D008297:Male; D008875:Middle Aged; D018911:Trinucleotide Repeats / Q000235:genetics
chemical_list: D051860:Fragile X Messenger Ribonucleoprotein 1; C497683:FMR1 protein, human