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ABSTRACT: Approximately 40% of males with the fragile X premutation develop fragile X-associated tremor/ataxia syndrome after age 50. Although the thalamus and basal ganglia play a crucial role in movement disorders, their involvement in fragile X premutation carriers has not been systematically investigated. The current study characterized structural abnormalities associated with fragile X premutation carriers (with and without fragile X-associated tremor/ataxia syndrome) in the thalamus, caudate nucleus, putamen, and globus pallidus using T1-weighted and diffusion tensor imaging. Male premutation carriers with fragile X-associated tremor/ataxia syndrome showed significant volume atrophy and diffusion-weighted signal loss in all 4 structures compared with the control group. They also exhibited volume atrophy and diffusion-weighted signal loss in the thalamus and striatum compared with the premutation carriers without fragile X-associated tremor/ataxia syndrome. Importantly, many of the measurements exhibited robust correlations with symptom severity, with volume and diffusion-weighted imaging measurements displaying negative correlations and fractional anisotropy measurements displaying positive correlations. The current study demonstrated involvement of all 4 subcortical gray matter structures in fragile X-associated tremor/ataxia syndrome, with significant volume atrophy, and possible iron deposition indicated by the diffusion-weighted signal loss. The significant correlation between the subcortical measurements and symptom severity suggests the benefits of tracking structural changes in subcortical gray matter in future longitudinal studies for early detection and disease monitoring. © 2013 Movement Disorder Society.
Movement Disorders 05/2013; · 4.51 Impact Factor
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Mary Jacena S Leigh,
Danh V Nguyen,
Yi Mu,
Tri I Winarni,
Andrea Schneider,
Tasleem Chechi,
Jonathan Polussa,
Paul Doucet,
Flora Tassone,
Susan M Rivera,
David Hessl, Randi J Hagerman
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ABSTRACT: OBJECTIVE:: Minocycline rescued synaptic abnormalities and improved behavior in the fragile X mouse model. Previous open-label human studies demonstrated benefits in individuals with fragile X syndrome (FXS); however, its efficacy in patients with FXS has not been assessed in a controlled trial. METHOD:: Randomized, double-blind, placebo-controlled, crossover trial in individuals with FXS, aged 3.5 years to 16 years (n = 55, mean age 9.2 [SD, 3.6] years). Participants were randomized to minocycline or placebo for 3 months and then switched to the other treatment. RESULTS:: Sixty-nine subjects were screened and 66 were randomized. Fifty-five subjects (83.3%) completed at least the first period and 48 (72.7%) completed the full trial. Intention-to-treat analysis demonstrated significantly greater improvements in one primary outcome, Clinical Global Impression Scale-Improvement after minocycline compared with placebo (2.49 ± 0.13 and 2.97 ± 0.13, respectively, p = .0173) and greater improvement in ad hoc analysis of anxiety and mood-related behaviors on the Visual Analog Scale (minocycline: 5.26 cm ± 0.46 cm, placebo: 4.05 cm ± 0.46 cm; p = .0488). Side effects were not significantly different during the minocycline and placebo treatments. No serious adverse events occurred on minocycline. Results may be potentially biased by study design weaknesses, including unblinding of subjects when they completed the study, drug-related side effects unblinding, and preliminary efficacy analysis results known to investigators. CONCLUSIONS:: Minocycline treatment for 3 months in children with FXS resulted in greater global improvement than placebo. Treatment for 3 months appears safe; however, longer trials are indicated to further assess benefits, side effects, and factors associated with a clinical response to minocycline.
Journal of developmental and behavioral pediatrics: JDBP 04/2013; 34(3):147-155. · 2.27 Impact Factor
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ABSTRACT: BACKGROUND: Fragile X testing is a priority in the evaluation of autism spectrum disorders (ASD) cases because identification of the FMR1 mutation leads to new treatment options. This study is focused on determining the prevalence of the FMR1 gene mutation among ASD cases in Indonesia. METHOD: DSM-IV-TR criteria were administered to diagnose ASD; symptom severity was classified using the Childhood Autism Rating Scale (CARS). Cytogenetic analysis, PCR, and Southern blot for FMR1 gene analysis were carried out to confirm the diagnosis of fragile X syndrome. RESULTS: The fragile X site and FMR1 full mutation allele were identified in 3 out of 65 (4.6%) and 4 out of 65 (6.15 %) children aged 3 to 17 years (57 boys, 8 girls) respectively. CONCLUSION: The Fragile X laboratory workup is essential in the evaluation of patients with ASD. Molecular analysis is most accurate, while cytogenetic documentation of the fragile X site can also be useful if molecular testing is not available.
Clinical Genetics 01/2013; · 3.13 Impact Factor
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David E Godler,
Yoshimi Inaba,
Elva Z Shi,
Cindy Skinner,
Quang M Bui,
David Francis,
David J Amor,
John L Hopper,
Danuta Z Loesch, Randi J Hagerman,
Charles E Schwartz,
Howard R Slater
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ABSTRACT: Methylation of the Fragile X Related Epigenetic Element 2 (FREE2) located on the exon 1 / intron 1 boundary of the FMR1 gene is related to FMRP expression and cognitive impairment in full mutation (FM - CGG>200) individuals. We examined the relationship between age, the size of the FMR1 CGG expansion and the methylation output ratio (MOR) at 12 CpG sites proximal to the exon 1 / intron 1 boundary using FREE2 MALDI-TOF MS. The patient cohort included 119 males and 368 females, i.e. 121 healthy controls (CGG<40), 176 premutation (CGG 55-170) and 190 FM (CGG 213-2000). For all CpG units examined, FM males showed a significantly elevated MOR compared to that in hypermethylated FM females. In FM males the MOR for most CpG units significantly positively correlated with both age and CGG size (p<0.05). In FM females the skewing towards the unmethylated state was significant for half of the units between birth and puberty (p<0.05). The methylation status of intron 1 CpG10-12 that was most significantly related to cognitive impairment in our earlier study, did not change significantly with age in FM females. These results challenge the concept of FXS related methylation being static over time, and suggest that due to the preference for the unmethylated state in FM females, X-inactivation at this locus is not random. The findings also highlight that the prognostic value of FXS methylation testing is not uniform between all CpG sites, and thus may need to be evaluated on a site by site basis.
Human Molecular Genetics 01/2013; · 7.64 Impact Factor
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Flora Tassone,
Ka Pou Long,
Tzu-Han Tong,
Joyce Lo,
Louise W Gane,
Elizabeth Berry-Kravis,
Danh Nguyen,
Lisa Y Mu,
Jennifer Laffin,
Don B Bailey, Randi J Hagerman
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ABSTRACT: BACKGROUND: Population screening for FMR1 mutations has been a topic of considerable discussion since the FMR1 gene was identified in 1991. Advances in understanding the molecular basis of fragile X syndrome (FXS) and in genetic testing methods have led to new, less expensive methodology to use for large screening endeavors. A core criterion for newborn screening is an accurate understanding of the public health burden of a disease, considering both disease severity and prevalence rate. This article addresses this need by reporting prevalence rates observed in a pilot newborn screening study for FXS in the US. METHODS: Blood spot screening of 14,207 newborns (7312 males and 6895 females) was conducted in three birthing hospitals across the United States beginning in November 2008, using a PCR-based approach. RESULTS: The prevalence of gray zone alleles was 1:66 females and 1:112 males, while the prevalence of a premutation was 1:209 females and 1:430 males. Differences in prevalence rates were observed among the various ethnic groups; specifically higher frequency for gray zone alleles in males was observed in the White group compared to the Hispanic and African-American groups. One full mutation male was identified (>200 CGG repeats). CONCLUSIONS: The presented pilot study shows that newborn screening in fragile X is technically feasible and provides overall prevalence of the premutation and gray zone alleles in the USA, suggesting that the prevalence of the premutation, particularly in males, is higher than has been previously reported.
Genome Medicine 12/2012; 4(12):100.
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ABSTRACT: We describe an ongoing pilot project in which newborn screening (NBS) for FMR1 mutations and subsequent cascade testing are performed by the MIND Institute at the University of California, Davis Medical Center (UCDMC). To date, out of 3,042 newborns initially screened, 44 extended family members have been screened by cascade testing of extended family members once a newborn is identified. Fourteen newborns (7 males and 7 females) and 27 extended family members (5 males and 22 females) have been identified with FMR1 mutations. Three family histories are discussed in detail, each demonstrating some benefits and risks of NBS and cascade testing for FMR1 mutations in extended family members. While we acknowledge inherent risks, we propose that with genetic counseling, clinical follow-up of identified individuals and cascade testing, NBS has significant benefits. Treatment for individuals in the extended family who would otherwise not have received treatment can be beneficial. In addition, knowledge of carrier status can lead to lifestyle changes and prophylactic interventions that are likely to reduce the risk of late onset neurological or psychiatric problems in carriers. Also with identification of carrier family members through NBS, reproductive choices become available to those who would not have known that they were at risk to have offspring with fragile X syndrome. © 2012 Wiley Periodicals, Inc.
American Journal of Medical Genetics Part A 12/2012; · 2.39 Impact Factor
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ABSTRACT: The fragile X mental retardation 1 (FMR1) gene plays an important role in the development and maintenance of neuronal circuits that are essential for cognitive functioning. We explored the functional linkage(s) among lymphocytic FMR1 gene expression, brain structure, and working memory in healthy adult males. We acquired T1-weighted and diffusion tensor imaging from 34 males (18-80years, mean±SD=43.6±18.4years) with normal FMR1 alleles and performed genetic and working memory assessments. Brain measurements were obtained from fiber tracts important for working memory (i.e. the arcuate fasciculus, anterior cingulum bundle, inferior longitudinal fasciculus, and the genu and anterior body of the corpus callosum), individual voxels, and whole brain. Both FMR1 mRNA and protein (FMRP) levels exhibited significant associations with brain measurements, with FMRP correlating positively with gray matter volume and white matter structural organization, and FMR1 mRNA negatively with white matter structural organization. The correlation was widespread, impacting rostral white matter and 2 working-memory fiber tracts for FMRP, and all cerebral white matter areas except the fornix and cerebellar peduncles and all 4 fiber tracts for FMR1 mRNA. In addition, the levels of FMR1 mRNA as well as the fiber tracts demonstrated a significant correlation with working memory performance. While FMR1 mRNA exhibited a negative correlation with working memory, fiber tract structural organization showed a positive correlation. These findings suggest that the FMR1 gene is a genetic factor common for both working memory and brain structure, and has implications for our understanding of the transmission of intelligence and brain structure.
NeuroImage 10/2012; · 5.89 Impact Factor
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Yoshimi Inaba,
Amy S Herlihy,
Charles E Schwartz,
Cindy Skinner,
Quang M Bui,
Joanna Cobb,
Elva Z Shi,
David Francis,
Alison Arvaj,
David J Amor,
Kate Pope,
Tiffany Wotton,
Jonathan Cohen,
Jacqueline K Hewitt, Randi J Hagerman,
Sylvia A Metcalfe,
John L Hopper,
Danuta Z Loesch,
Howard R Slater,
David E Godler
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ABSTRACT: Purpose:We show that a novel fragile X-related epigenetic element 2 FMR1 methylation test can be used along with a test for sex-determining region Y (SRY) to provide the option of combined fragile X syndrome and sex chromosome aneuploidy newborn screening.Methods:Fragile X-related epigenetic element 2, SRY, and FMR1 CGG repeat analyses were performed on blood and saliva DNA, and in adult and newborn blood spots. The cohort consisted of 159 controls (CGG <40), 187 premutation (CGG 56-170), and 242 full-mutation (CGG ~200-2,000) males and females, 106 sex chromosome aneuploidy individuals, and 151 cytogenetically normal controls.Results:At the 0.435 threshold, fragile X-related epigenetic element 2 analysis in males was robust on both blood DNA and newborn blood spots, with specificity and sensitivity of ~100% for full-mutation genotype. In females, the specificity was 99%, whereas half of full-mutation females were above the 0.435 threshold in both blood DNA and newborn blood spots. Furthermore, at this threshold, the test could not differentiate individuals with Klinefelter syndrome from female controls without using the SRY marker. When combined with SRY analysis, the test was consistent with most results for sex chromosome aneuploidies from karyotyping.Conclusion:Setting specific thresholds for fragile X-related epigenetic element 2 analysis and including the SRY marker provides the option to either include or exclude detection of sex chromosome aneuploidies as part of fragile X syndrome newborn screening.Genet Med advance online publication 11 October 2012Genetics in Medicine (2012); doi:10.1038/gim.2012.134.
Genetics in medicine: official journal of the American College of Medical Genetics 10/2012; · 3.92 Impact Factor
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Elizabeth M Berry-Kravis,
David Hessl,
Barbara Rathmell,
Peter Zarevics,
Maryann Cherubini,
Karen Walton-Bowen,
Yi Mu,
Danh V Nguyen,
Joseph Gonzalez-Heydrich,
Paul P Wang,
Randall L Carpenter,
Mark F Bear, Randi J Hagerman
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ABSTRACT: Research on animal models of fragile X syndrome suggests that STX209, a γ-aminobutyric acid type B (GABA(B)) agonist, might improve neurobehavioral function in affected patients. We evaluated whether STX209 improves behavioral symptoms of fragile X syndrome in a randomized, double-blind, placebo-controlled crossover study in 63 subjects (55 male), ages 6 to 39 years, with a full mutation in the FMR1 gene (>200 CGG triplet repeats). We found no difference from placebo on the primary endpoint, the Aberrant Behavior Checklist-Irritability (ABC-I) subscale. In the other analyses specified in the protocol, improvement was seen on the visual analog scale ratings of parent-nominated problem behaviors, with positive trends on multiple global measures. Post hoc analysis with the ABC-Social Avoidance scale, a newly validated scale for the assessment of fragile X syndrome, showed a significant beneficial treatment effect in the full study population. A post hoc subgroup of 27 subjects with more severe social impairment showed improvements on the Vineland II-Socialization raw score, on the ABC-Social Avoidance scale, and on all global measures. STX209 was well tolerated, with 8% incidences of sedation and of headache as the most frequent side effects. In this exploratory study, STX209 did not show a benefit on irritability in fragile X syndrome. Nonetheless, our results suggest that GABA(B) agonists have potential to improve social function and behavior in patients with fragile X syndrome.
Science translational medicine 09/2012; 4(152):152ra127. · 7.80 Impact Factor
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Jin-Chen Yang,
Shiao-Hui Chan,
Sara Khan,
Andrea Schneider,
Rawi Nanakul,
Sara Teichholtz,
Yu-Qiong Niu,
Andreea Seritan,
Flora Tassone,
Jim Grigsby,
Paul J Hagerman, Randi J Hagerman,
John M Olichney
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ABSTRACT: Executive dysfunction in fragile X-associated tremor/ataxia syndrome (FXTAS) has been suggested to mediate other cognitive impairments. In the present study, event-related potentials and neuropsychological testing were combined to investigate the brain mechanisms underlying the executive dysfunction in FXTAS. Thirty-two-channel electroencephalography was recorded during an auditory "oddball" task requiring dual responses. FXTAS patients (N= 41, mean age= 62) displayed prolonged latencies of N1 and P3 and reduced amplitudes of P2 and P3, whereas their N2 measures remained within the normal range, indicating relatively preserved early-stage auditory attention but markedly impaired late-stage attention and working memory updating processes (as indexed by P3). Topographical mapping revealed a typical parietal P3 peak preceded by a prominent fronto-central P3 in normal control subjects (N= 32), whereas FXTAS patients had decreased parietal P3 amplitude and diminished fronto-central positivities with a delayed onset (∼50 ms later than controls, P < 0.002). The P3 abnormalities were associated with lower executive function test (e.g., BDS-2) scores. Smaller P3 amplitudes also correlated with increased CGG repeat length of fragile X mental retardation 1 (FMR1) gene and higher FMR1 mRNA levels. These results indicate that abnormal fronto-parietal attentional network dynamics underlie executive dysfunction, the cardinal feature of cognitive impairment in FXTAS.
Cerebral Cortex 08/2012; · 6.54 Impact Factor
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Tri Indah Winarni,
Weerasak Chonchaiya,
Tanjung Ayu Sumekar,
Paul Ashwood,
Guadalupe Mendoza Morales,
Flora Tassone,
Danh V Nguyen,
Sultana M H Faradz,
Judy Van de Water,
Kylee Cook,
Alyssa Hamlin,
Yi Mu,
Paul J Hagerman, Randi J Hagerman
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ABSTRACT: The relative risk of immune-mediated disorders (IMDs) among women carriers of premutation alleles is estimated by a survey for IMDs among 344 carrier women (age 19-81 years; mean 46.35 and SD 12.60) and 72 controls (age 18-87 years; mean 52.40 and SD 15.40). One hundred fifty four (44.77%) women carrier had at least one IMD, as did 20 controls (27.78%). Among women carriers, autoimmune thyroid disorder was the most common (24.4%), then fibromyalgia (10.2%), irritable bowel syndrome (IBS; 9.9%), Raynaud's phenomenon (7.6%), rheumatoid arthritis (RA; 3.8%), Sjögren syndrome (2.6%), systemic lupus erythematosus (SLE; 2.03%), multiple sclerosis (1.74%). Of 55 carriers age 40 or older with FXTAS, 72.73% had at least one IMD, compared to 46.54% of those without FXTAS (n = 159), and 31.58% of controls (n = 57). The estimated odds ratio (OR) for IMD is 2.6 (95% CI 1.2-5.6, P = 0.015) for women with FXTAS relative to those without FXTAS; the likelihood of IMD in carriers without or with FXTAS was also significantly higher than for controls (OR 2.1, 95% CI 1.1-4.2, P = 0.034; OR 5.5, 95% CI 2.4-12.5, P < 0.001, respectively). Similarly, the odds of having an IMD among carriers with FXPOI is about 2.4 times higher when compared to carriers without FXPOI (95% CI 1.1-5.0; P = 0.021). The likelihood of IMD in carriers with or without FXPOI is greater (OR 2.4, 95% CI 1.1-5.0; P = 0.021) compared to that of controls. © 2012 Wiley Periodicals, Inc.
American Journal of Medical Genetics Part A 08/2012; 158A(10):2473-81. · 2.39 Impact Factor
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Jing Liu,
Katarzyna A Koscielska,
Zhengyu Cao,
Susan Hulsizer,
Natalie Grace,
Gaela Mitchell,
Catherine Nacey,
Jackline Githinji,
Jeannine McGee,
Dolores Garcia-Arocena, Randi J Hagerman,
Jan Nolta,
Isaac N Pessah,
Paul J Hagerman
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ABSTRACT: Fragile X-associated tremor/ataxia syndrome (FXTAS) is a leading monogenic neurodegenerative disorder affecting premutation carriers of the fragile X (FMR1) gene. To investigate the underlying cellular neuropathology, we produced induced pluripotent stem cell-derived neurons from isogenic subclones of primary fibroblasts of a female premutation carrier, with each subclone bearing exclusively either the normal or the expanded (premutation) form of the FMR1 gene as the active allele. We show that neurons harboring the stably-active, expanded allele (EX-Xa) have reduced postsynaptic density protein 95 protein expression, reduced synaptic puncta density and reduced neurite length. Importantly, such neurons are also functionally abnormal, with calcium transients of higher amplitude and increased frequency than for neurons harboring the normal-active allele. Moreover, a sustained calcium elevation was found in the EX-Xa neurons after glutamate application. By excluding the individual genetic background variation, we have demonstrated neuronal phenotypes directly linked to the FMR1 premutation. Our approach represents a unique isogenic, X-chromosomal epigenetic model to aid the development of targeted therapeutics for FXTAS, and more broadly as a model for the study of common neurodevelopmental (e.g. autism) and neurodegenerative (e.g. Parkinsonism, dementias) disorders.
Human Molecular Genetics 05/2012; 21(17):3795-805. · 7.64 Impact Factor
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ABSTRACT: Fragile X-associated tremor ataxia syndrome (FXTAS) is a late onset neurodegenerative disease that affects carriers of the fragile X premutation. This study seeks to assess hypertension risk and susceptibility in male premutation carriers with FXTAS. Although many symptoms and diagnostic criteria have been identified, hypertension risk has not been examined in this population. Data from 92 premutation carriers without FXTAS, 100 premutation carriers with FXTAS, and 186 controls was collected via patient medical interview. Age-adjusted logistic regression analysis was used to examine the relative odds of hypertension. We observed a significantly elevated odds ratio (OR) of hypertension relative to controls for premutation carriers with FXTAS (OR = 3.22, 95% CI: 1.72-6.04; P = 0.0003) among participants over 40-year old. The age-adjusted estimated odds of hypertension in premutation carriers without FXTAS in the over 40-year-old age group was higher compared to controls (OR = 1.61, 95% CI: 0.82-3.16), but was not statistically significant (P = 0.164). Chronic hypertension contributes to cardiovascular complications, dementia, and increased risk of stroke. Our results indicate that the risk of hypertension is significantly elevated in male premutation carriers with FXTAS compared with carriers without FXTAS and controls. Thus, evaluation of hypertension in patients diagnosed with FXTAS should be a routine part of the treatment monitoring and intervention for this disease.
American Journal of Medical Genetics Part A 04/2012; 158A(6):1304-9. · 2.39 Impact Factor
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ABSTRACT: We reported previously that 10 older men (66.4 ± 4.6 years) with premutation alleles (55-200 CGG repeats) of the FMR1 gene, with or without FXTAS, had decreased telomere length when compared to sex- and age-matched controls. Extending our use of light intensity measurements from a telomere probe hybridized to interphase preparations, we have now found shortened telomeres in 9 younger male premutation carriers (31.7 ± 17.6 years). We have also shown decreased telomere length in T lymphocytes from 6 male individuals (12.0 ± 1.8 years) with full mutation FMR1 alleles (>200 CGG repeats). These findings support our hypothesis that reduced telomere length is a component of the sub-cellular pathology of FMR1-associated disorders. The experimental approach involved pair-wise comparisons of light intensity values of 20 cells from an individual with either premutation or full mutation CGG-repeat expansions relative to an equivalent number of cells from a sex- and age-matched control. In addition, we demonstrated reduced telomere size in T-lymphocyte cultures from eight individuals with the FMR1 premutation using six different measures. Four relied on detection of light intensity differences, and two involved measuring the whole chromosome, including the telomere, in microns. This new approach confirmed our findings with light intensity measurements and demonstrated the feasibility of direct linear measurements for detecting reductions in telomere size. We have thus confirmed our hypothesis that reduced telomere length is associated with both premutation and full mutation-FMR1 alleles and have demonstrated that direct measurements of telomere length can reliably detect such reductions.
American Journal of Medical Genetics Part A 04/2012; 158A(5):1060-5. · 2.39 Impact Factor
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ABSTRACT: Premutation CGG repeat expansions (55-200 CGG repeats; preCGG) within the fragile X mental retardation 1 (FMR1) gene cause fragile X-associated tremor/ataxia syndrome (FXTAS). Defects in neuronal morphology and migration have been described in a preCGG mouse model. Mouse preCGG hippocampal neurons (170 CGG repeats) grown in vitro develop abnormal networks of clustered burst (CB) firing, as assessed by multielectrode array recordings and clustered patterns of spontaneous Ca(2+) oscillations, neither typical of wild-type (WT) neurons. PreCGG neurons have reduced expression of vesicular GABA and glutamate (Glu) transporters (VGAT and VGLUT1, respectively), and preCGG hippocampal astrocytes display a rightward shift on Glu uptake kinetics, compared with WT. These alterations in preCGG astrocytes and neurons are associated with 4- to 8-fold elevated Fmr1 mRNA and occur despite consistent expression of fragile X mental retardation protein levels at ∼50% of WT levels. Abnormal patterns of activity observed in preCGG neurons are pharmacologically mimicked in WT neurons by addition of Glu or the mGluR1/5 agonist, dihydroxyphenylglycine, to the medium, or by inhibition of astrocytic Glu uptake with dl-threo-β-benzyloxyaspartic acid, but not by the ionotropic Glu receptor agonists, α-2-amino-3-(5-methyl-3-oxo-1,2-oxazol-4-yl) propanoic acid or N-methyl-d-aspartic acid. The mGluR1 (7-(hydroxyimino)cyclopropa [b]chromen-1a-carboxylate ethyl ester) or mGluR5 (2-methyl-6-(phenylethynyl)pyridine hydrochloride) antagonists reversed CB firing. Importantly, the acute addition of the neurosteroid allopregnanolone mitigated functional impairments observed in preCGG neurons in a reversible manner. These results demonstrate abnormal mGluR1/5 signaling in preCGG neurons, which is ameliorated by mGluR1/5 antagonists or augmentation of GABA(A) receptor signaling, and identify allopregnanolone as a candidate therapeutic lead.
Human Molecular Genetics 04/2012; 21(13):2923-35. · 7.64 Impact Factor
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ABSTRACT: OBJECTIVE To examine the effects of premutation alleles on major brain fiber tracts in males. DESIGN Cross-sectional study performed in 2007-2009. SETTING Institutional practice. PATIENTS Fifteen younger (18-45 years old) carriers, 11 older (>45 years old) unaffected carriers, and 15 older carriers with fragile X-associated tremor/ataxia syndrome, together with 19 younger and 15 older controls matched by age and educational level. MAIN OUTCOME MEASURES Diffusion tensor imaging was performed on all study participants. Eleven fiber tracts important for motor, social, emotional, and cognitive functions were reconstructed and quantified. Complementary tract-based spatial statistical analyses were performed in core white matter. RESULTS In the younger carriers, premutation status was associated with a greater age-related connectivity decline in the extreme capsule. Among older carriers, unaffected individuals did not display structural alterations, whereas the affected carriers showed connectivity loss in 5 fiber tracts and exhibited greater age-related connectivity decline in all 11 tracts compared with the controls. In addition, 9 fiber tracts showed significantly higher variability relative to the controls, and symptom severity explained the variability in 6 measurements from the superior cerebellar peduncle, corpus callosum, and cingulum. CONCLUSIONS The findings revealed widespread alterations in structural connectivity associated with fragile X-associated tremor/ataxia syndrome and preserved or subtle changes in structural connectivity in unaffected carriers. Diffusion tensor imaging is sensitive to pathologic changes in the white matter associated with this neurodegenerative disorder.
Archives of neurology 04/2012; 69(4):482-9. · 6.31 Impact Factor
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ABSTRACT: To examine the effects of premutation alleles on major brain fiber tracts in males.
Cross-sectional study performed in 2007-2009.
Institutional practice.
Fifteen younger (18-45 years old) carriers, 11 older (>45 years old) unaffected carriers, and 15 older carriers with fragile X-associated tremor/ataxia syndrome, together with 19 younger and 15 older controls matched by age and educational level.
Diffusion tensor imaging was performed on all study participants. Eleven fiber tracts important for motor, social, emotional, and cognitive functions were reconstructed and quantified. Complementary tract-based spatial statistical analyses were performed in core white matter.
In the younger carriers, premutation status was associated with a greater age-related connectivity decline in the extreme capsule. Among older carriers, unaffected individuals did not display structural alterations, whereas the affected carriers showed connectivity loss in 5 fiber tracts and exhibited greater age-related connectivity decline in all 11 tracts compared with the controls. In addition, 9 fiber tracts showed significantly higher variability relative to the controls, and symptom severity explained the variability in 6 measurements from the superior cerebellar peduncle, corpus callosum, and cingulum.
The findings revealed widespread alterations in structural connectivity associated with fragile X-associated tremor/ataxia syndrome and preserved or subtle changes in structural connectivity in unaffected carriers. Diffusion tensor imaging is sensitive to pathologic changes in the white matter associated with this neurodegenerative disorder. Wang et al examine the effects of premutation alleles on major brain fiber tracts in males, who are at risk of developing fragile X-associated tremor/ataxia syndrome and may manifest subtle cognitive, social, and emotional disturbances before clinical involvement.
Archives of neurology 04/2012; 69(4):482-9. · 6.31 Impact Factor
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David E Godler,
Howard R Slater,
Quang M Bui,
Elsdon Storey,
Michele Y Ono,
Freya Gehling,
Yoshimi Inaba,
David Francis,
John L Hopper,
Glynda Kinsella,
David J Amor, Randi J Hagerman,
Danuta Z Loesch
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ABSTRACT: Cognitive status in females with mutations in the FMR1 (fragile X mental retardation 1) gene is highly variable. A biomarker would be of value for predicting which individuals were liable to develop cognitive impairment and could benefit from early intervention. A detailed analysis of CpG sites bridging exon 1 and intron 1 of FMR1, known as fragile X-related epigenetic element 2 (FREE2), suggests that a simple blood test could identify these individuals.
Study participants included 74 control females (<40 CGG repeats), 62 premutation (PM) females (55-200 CGG repeats), and 18 full-mutation (FM) females assessed with Wechsler intelligence quotient (IQ) tests. We used MALDI-TOF mass spectrometry to determine the methylation status of FREE2 CpG sites that best identified low-functioning (IQ <70) FM females (>200 CGG repeats), compared the results with those for Southern blot FMR1 activation ratios, and related these assessments to the level of production of the FMR1 protein product in blood.
A methylation analysis of intron 1 CpG sites 10-12 showed the highest diagnostic sensitivity (100%) and specificity (98%) of all the molecular measures tested for detecting females with a standardized verbal IQ of <70 among the study participants. In the group consisting of only FM females, methylation of these sites was significantly correlated with full-scale IQ, verbal IQ, and performance IQ. Several verbal subtest scores showed strong correlation with the methylation of these sites (P = 1.2 × 10(-5)) after adjustment for multiple measures.
The data suggest that hypermethylation of the FMR1 intron 1 sites in blood is predictive of cognitive impairment in FM females, with implications for improved fragile X syndrome diagnostics in young children and screening of the newborn population.
Clinical Chemistry 03/2012; 58(3):590-8. · 7.91 Impact Factor
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ABSTRACT: Fragile X syndrome (FXS) is the most common inherited cause of intellectual disability due to an expansion in the full mutation range (>200 CGG repeats) of the promoter region of the FMR1 gene leading to gene silencing. Lack of FMRP, a critical protein for dendritic spine formation and maturation, will cause FXS. Early environmental enrichment combined with pharmacological intervention has been proven to rescue dendritic spine abnormalities in the animal model of FXS. Here we report on 2 young children with FXS who were treated early with a combination of targeted treatment and intensive educational interventions leading to improvement in their cognition and behavior and a normal IQ.
Case reports in genetics. 01/2012; 2012:280813.
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ABSTRACT: Young children with fragile X syndrome (FXS) often experience anxiety, irritability, and hyperactivity related to sensory hyperarousal. However, there are no medication recommendations with documented efficacy for children under 5 years old of age with FXS. We examined data through a chart review for 45 children with FXS, 12-50 months old, using the Mullen Scales of Early Learning (MSEL) for baseline and longitudinal assessments. All children had clinical level of anxiety, language delays based on MSEL scores, and similar early learning composite (ELC) scores at their first visit to our clinic. Incidence of autism spectrum disorder (ASD) was similar in both groups. There were 11 children who were treated with sertraline, and these patients were retrospectively compared to 34 children who were not treated with sertraline by chart review. The baseline assessments were done at ages ranging from 18 to 44 months (mean 26.9, SD 7.99) and from 12 to 50 months (mean 29.94, SD 8.64) for treated and not treated groups, respectively. Mean rate of improvement in both expressive and receptive language development was significantly higher in the group who was treated with sertraline (P < 0.0001 and P = 0.0071, resp.). This data supports the need for a controlled trial of sertraline treatment in young children with FXS.
Autism research and treatment. 01/2012; 2012:104317.
