The Fragile X-Associated Tremor/Ataxia Syndrome (FXTAS) is a neurologic disorder that affects males with premutation expansion of CGG repeats in the FMR1 gene. Jacquemont et al identified clinical findings that can identify males who should have genetic testing. The authors are from the University of California Davis, University of Colorado, San Diego State University and Rush-Presbyterian St. Luke's Medical Center (Chicago).


Gene affected: FMR1 (Fragile X Mental Retardation 1) on the X-chromosome


Number of CGG repeats in FMR1 gene: 55 to 200


Estimated frequency: 1 in 3,000 males over the age of 50


Key clinical findings:

(1) male >= 50 years of age

(2) cerebellar ataxia, resulting in gait and balance problems

(3) intention tremor


Variable findings:

(1) short-term memory loss

(2) executive functional defects

(3) cognitive decline

(4) Parkinsonism

(5) peripheral neuropathy

(6) proximal muscle weakness in the lower limbs

(7) autonomic dysfunction


A male with the clinical phenotype should have testing of the FMR1 gene.


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