Screen for expanded FMR1 alleles in patients with essential tremor.
Fragile X-associated tremor/ataxia syndrome (FXTAS), a neurodegenerative disorder, was described recently among male carriers of expanded alleles (55-200 CGG repeats; premutation range) of the fragile X mental retardation 1 (FMR1) gene. Major features of the syndrome include intention tremor, gait ataxia, and parkinsonism in men over 50 years of age. This disorder is believed to be relatively common, possibly affecting 1 in 3,000 men over the age of 50 years in the general population. This raises the possibility that some patients presenting with essential tremor (ET) may harbor expanded FMR1 alleles. We screened 81 ET patients (40 males, 41 females) for expanded FMR1 alleles to determine whether ET is associated with such alleles. None of the ET cases had the premutation genotype. CGG repeat sizes ranged from 5 to 47 repeats within this study population, suggesting that expanded FMR1 alleles are uncommon among patients with ET. Screening of movement disorder patients with other clinical features of FXTAS (e.g., ataxia and parkinsonism) may be more likely to yield expanded FMR1 alleles.
Department of Biological Chemistry, University of California, Davis, School of Medicine, Davis, California 95616, USA. dolgarcia@ucdavis.edu
Dolores
D
Garcia Arocena
Elan D
ED
Louis
Flora
F
Tassone
T Conrad
TC
Gilliam
Ruth
R
Ottman
Sébastien
S
Jacquemont
Paul J
PJ
Hagerman
D000368:Aged; D000369:Aged, 80 and over; D000483:Alleles; D015139:Blotting, Southern / Q000379:methods; D020329:Essential Tremor / Q000235:genetics*; D005260:Female; D051860:Fragile X Messenger Ribonucleoprotein 1; D005820:Genetic Testing / Q000379:methods; D005838:Genotype; D006801:Humans; D008297:Male; D008875:Middle Aged; D009419:Nerve Tissue Proteins / Q000235:genetics*; D012333:RNA, Messenger / Q000096:biosynthesis; D016601:RNA-Binding Proteins / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods; D019680:Trinucleotide Repeat Expansion / Q000235:genetics*
D051860:Fragile X Messenger Ribonucleoprotein 1; D009419:Nerve Tissue Proteins; D012333:RNA, Messenger; D016601:RNA-Binding Proteins; C497683:FMR1 protein, human