Impact of the Fragile X mental retardation 1 (FMR1) gene premutation on neuropsychiatric functioning in adult males without fragile X-associated Tremor/Ataxia syndrome: A controlled study

2007 ◽  
Vol 147B (6) ◽  
pp. 859-872 ◽  
Author(s):  
Cary S. Kogan ◽  
Jeremy Turk ◽  
Randi J. Hagerman ◽  
Kim M. Cornish
2018 ◽  
Vol 4 (4) ◽  
pp. e246 ◽  
Author(s):  
Padmaja Vittal ◽  
Shrikant Pandya ◽  
Kevin Sharp ◽  
Elizabeth Berry-Kravis ◽  
Lili Zhou ◽  
...  

ObjectiveTo explore the association of a splice variant of theantisense fragile X mental retardation 1(ASFMR1) gene, loss offragile X mental retardation 1(FMR1) AGG interspersions andFMR1CGG repeat size with manifestation, and severity of clinical symptoms of fragile X-associated tremor/ataxia syndrome (FXTAS).MethodsPremutation carriers (PMCs) with FXTAS, without FXTAS, and normal controls (NCs) had a neurologic evaluation and collection of skin and blood samples. Expression ofASFMR1transcript/splice variant 2 (ASFMR1-TV2), nonsplicedASFMR1, totalASFMR1, andFMR1messenger RNA were quantified and compared using analysis of variance. Least absolute shrinkage and selection operator (LASSO) logistic regression and receiver operating characteristic analyses were performed.ResultsPremutation men and women both with and without FXTAS had higherASFMR1-TV2 levels compared with NC men and women (n = 135,135,p< 0.0001), andASFMR1-TV2 had good discriminating power for FXTAS compared with NCs but not for FXTAS from PMC. After adjusting for age, loss of AGG, larger CGG repeat size (in men), and elevatedASFMR1-TV2 level (in women) were strongly associated with FXTAS compared with NC and PMC (combined).ConclusionsThis study found elevated levels ofASFMR1-TV2and loss of AGG interruptions in both men and women with FXTAS. Future studies will be needed to determine whether these variables can provide useful diagnostic or predictive information.


RNA Biology ◽  
2007 ◽  
Vol 4 (2) ◽  
pp. 93-100 ◽  
Author(s):  
Marta Zumwalt ◽  
Anna Ludwig ◽  
Paul J. Hagerman ◽  
Thorsten Dieckmann

2019 ◽  
Vol 15 (4) ◽  
pp. 251-258 ◽  
Author(s):  
Dragana Protic ◽  
Maria J. Salcedo-Arellano ◽  
Jeanne Barbara Dy ◽  
Laura A. Potter ◽  
Randi J. Hagerman

Fragile X Syndrome (FXS) is the most common cause of inherited intellectual disability with prevalence rates estimated to be 1:5,000 in males and 1:8,000 in females. The increase of >200 Cytosine Guanine Guanine (CGG) repeats in the 5’ untranslated region of the Fragile X Mental Retardation 1 (FMR1) gene results in transcriptional silencing on the FMR1 gene with a subsequent reduction or absence of fragile X mental retardation protein (FMRP), an RNA binding protein involved in the maturation and elimination of synapses. In addition to intellectual disability, common features of FXS are behavioral problems, autism, language deficits and atypical physical features. There are still no currently approved curative therapies for FXS, and clinical management continues to focus on symptomatic treatment of comorbid behaviors and psychiatric problems. Here we discuss several treatments that target the neurobiological pathway abnormal in FXS. These medications are clinically available at present and the data suggest that these medications can be helpful for those with FXS.


2016 ◽  
Vol 10 ◽  
Author(s):  
Eleonora Napoli ◽  
Catherine Ross-Inta ◽  
Gyu Song ◽  
Sarah Wong ◽  
Randi Hagerman ◽  
...  

2009 ◽  
Vol 9 (4) ◽  
pp. 116-118 ◽  
Author(s):  
Lisa R. Merlin

Correction of Fragile X Syndrome in Mice. Dölen G, Osterweil E, Rao BSS, Smith GB, Auerbach BD, Chattarji S, Bear MF. Neuron 2007;56:955–962. Fragile X syndrome (FXS) is the most common form of heritable mental retardation and the leading identified cause of autism. FXS is caused by transcriptional silencing of the FMR1 gene that encodes the fragile X mental retardation protein (FMRP), but the pathogenesis of the disease is unknown. According to one proposal, many psychiatric and neurological symptoms of FXS result from unchecked activation of mGluR5, a metabotropic glutamate receptor. To test this idea we generated Fmr1 mutant mice with a 50% reduction in mGluR5 expression and studied a range of phenotypes with relevance to the human disorder. Our results demonstrate that mGluR5 contributes significantly to the pathogenesis of the disease, a finding that has significant therapeutic implications for fragile X and related developmental disorders. Limbic Epileptogenesis in a Mouse Model of Fragile X Syndrome. Qiu LF, Lu TJ, Hu XL, Yi YH, Liao WP, Xiong ZQ. Cereb Cortex 2009 in press. (doi:10.1093/cercor/bhn163) Fragile X syndrome (FXS), caused by silencing of the Fmr1 gene, is the most common form of inherited mental retardation. Epilepsy is reported to occur in 20–25% of individuals with FXS. However, no overall increased excitability has been reported in Fmr1 knockout (KO) mice, except for increased sensitivity to auditory stimulation. Here, we report that kindling increased the expressions of Fmr1 mRNA and protein in the forebrain of wild-type (WT) mice. Kindling development was dramatically accelerated in Fmr1 KO mice, and Fmr1 KO mice also displayed prolonged electrographic seizures during kindling and more severe mossy fiber sprouting after kindling. The accelerated rate of kindling was partially repressed by inhibiting N-methyl-D-aspartic acid receptor (NMDAR) with MK-801 or mGluR5 receptor with 2-methyl-6-(phenylethynyl)-pyridine (MPEP). The rate of kindling development in WT was not effected by MPEP, however, suggesting that FMRP normally suppresses epileptogenic signaling downstream of metabotropic glutamate receptors. Our findings reveal that FMRP plays a critical role in suppressing limbic epileptogenesis and predict that the enhanced susceptibility of patients with FXS to epilepsy is a direct consequence of the loss of an important homeostatic factor that mitigates vulnerability to excessive neuronal excitation.


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