Abstract
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.
Original language | English (US) |
---|---|
Pages (from-to) | 74-77 |
Number of pages | 4 |
Journal | Clinical Genetics |
Volume | 84 |
Issue number | 1 |
DOIs | |
State | Published - Jul 2013 |
Keywords
- Ataxia
- FMR1-mRNA
- FXTAS
- Grey zone
- Premutation
- Tremor
ASJC Scopus subject areas
- Genetics(clinical)
- Genetics