Send to

Choose Destination
Clin Genet. 2013 Jul;84(1):74-7. doi: 10.1111/cge.12026. Epub 2012 Oct 17.

Fragile X-associated tremor/ataxia syndrome (FXTAS) in grey zone carriers.

Author information

Department of Neurology, Dalian Municipal Friendship Hospital, Dalian, PR China.


The grey zone (GZ; 45-54 CGG repeats in the FMR1 gene) is considered a normal allele; however, several studies have found a high frequency of GZ in movement disordered populations. Here, we describe neurological features of fragile X-associated tremor/ataxia syndrome (FXTAS) in two carriers of GZ alleles, although FXTAS has been defined as occurring only in premutation carriers (55-200 CGG repeats). Both patients had family members who had premutation and were diagnosed with FXTAS. The presence of relatively high GZ alleles with elevated fragile X mental retardation 1 mRNA (FMR1-mRNA) combined with a family history of FXTAS that may represent a facilitating genetic background for FXTAS are the factors that led to the presence of FXTAS in these individuals with a GZ allele. Further research into clinical involvement of GZ alleles is recommended and the definition of FXTAS may require revision.

[Indexed for MEDLINE]
Free PMC Article

Conflict of interest statement

There are no other conflicts of interest from the authors.

Supplemental Content

Full text links

Icon for Wiley Icon for PubMed Central
Loading ...
Support Center