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Case Reports
. 2012 Feb;27(2):296-300.
doi: 10.1002/mds.24021. Epub 2011 Dec 11.

Fragile X-associated tremor ataxia syndrome in FMR1 gray zone allele carriers

Deborah Hall  1 , Flora Tassone, Olga Klepitskaya, Maureen Leehey
Affiliations
Case Reports

Fragile X-associated tremor ataxia syndrome in FMR1 gray zone allele carriers

Deborah Hall et al. Mov Disord. 2012 Feb.

Abstract

Background: Carriers of fragile X mental retardation 1 (FMR1) repeat expansions in the premutation range (55-200 CGG repeats) often develop a syndrome of kinetic tremor, cerebellar ataxia, and parkinsonism; designated the fragile X-associated tremor ataxia syndrome (FXTAS). Neurological signs have not been reported in carriers of gray zone (45-54 CGG repeats) expansions.

Methods/results: We describe 3 patients with FMR1 gray zone alleles who meet diagnostic criteria for FXTAS.

Conclusions: Our cases suggest that the definition of the FXTAS may need to be broadened to include individuals with FMR1 repeat expansions in the gray zone. These neurological signs may be due to elevated levels of expanded CGG repeat FMR1 mRNA in the gray zone carriers, similar to the changes seen in premutation carriers with FXTAS.

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Figures

Figure 1
Figure 1
Spirals from the Clinical Rating Scale for Tremor: a. Case 1 b. Case 2.
Figure 1
Figure 1
Spirals from the Clinical Rating Scale for Tremor: a. Case 1 b. Case 2.
Figure 2
Figure 2
Case 2: a. Axial T2-weighted fast spin ECHO MRI showing basal ganglia hypodensities and volume loss Case 3: b. Axial T2-weighted MRI showing hyperintensities in the middle cerebellar peduncle (‘MCP sign’) c. Coronal FLAIR MRI showing hyperintensities in the middle cerebellar peduncle.
Figure 2
Figure 2
Case 2: a. Axial T2-weighted fast spin ECHO MRI showing basal ganglia hypodensities and volume loss Case 3: b. Axial T2-weighted MRI showing hyperintensities in the middle cerebellar peduncle (‘MCP sign’) c. Coronal FLAIR MRI showing hyperintensities in the middle cerebellar peduncle.
Figure 2
Figure 2
Case 2: a. Axial T2-weighted fast spin ECHO MRI showing basal ganglia hypodensities and volume loss Case 3: b. Axial T2-weighted MRI showing hyperintensities in the middle cerebellar peduncle (‘MCP sign’) c. Coronal FLAIR MRI showing hyperintensities in the middle cerebellar peduncle.
See this image and copyright information in PMC

References

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