Fragile X Syndrome Research Today is a free monthly online journal that collates and summarizes the latest research about Fragile X Syndrome, including details on symptoms, treatment, heritability, diagnosis.

Subregion-specific dendritic spine abnormalities in the hippocampus of Fmr1 KO mice.

Levenga J, de Vrij FM, Buijsen RA, Li T, Nieuwenhuizen IM, Pop A, Oostra BA, Willemsen R

CBG-Department of Clinical Genetics, Erasmus MC, Dr. Molewaterplein 50, 3015 GE Rotterdam, The Netherlands.

Fragile X syndrome (FXS) is the most common inherited form of mental retardation and is caused by the lack of fragile X mental retardation protein (FMRP). In the brain, spine abnormalities have been reported in both patients with FXS and Fmr1 knockout mice. This altered spine morphology has been linked to disturbed synaptic transmission related to altered signaling in the excitatory metabotropic glutamate receptor 5 (mGluR5) pathway. We investigated hippocampal protrusion morphology in adult Fmr1 knockout mice. Our results show a hippocampal CA1-specific altered protrusion phenotype, which was absent in the CA3 region of the hippocampus. This suggests a subregion-specific function of FMRP in synaptic plasticity in the brain.

Published 2 May 2011 in Neurobiol Learn Mem, 95(4): 467-72.
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Articles on Fragile X Syndrome published 2 May 2011:

Health supervision for children with fragile x syndrome.   Pediatrics, 127(5): 994-1006.

Fragile X syndrome (an FMR1-related disorder) is the most commonly inherited form of mental retardation. Early physical recognition is difficult, so boys with developmental delay should be strongly considered for molecular testing. The characteristic adult phenotype usually does not develop until the second decade of life. Girls can also be affected with developmental delay. Because multiple family members can be affected with mental retardation and other conditions (premature ovarian failure ... [Abstract] [Full-text]

Articles on Fragile X Syndrome published 29 April 2011:

Psychiatric and Autistic Comorbidity in Fragile X Syndrome Across Ages.   J Child Neurol.

Fragile X syndrome is caused by CGG trinucleotide repeat expansion within the fragile X mental retardation 1 gene, when repeat number exceeds 200. The typical psychiatric profile of fragile X syndrome patients includes cognitive and behavioral deficits, psychiatric comorbidity, and autistic characteristics. Specific psychiatric features have not yet been clarified, specifically in relationship to age and genetic characteristics. The objective of this study was to characterize psychiatric ... [Abstract] [Full-text]

Articles on Fragile X Syndrome published 28 April 2011:

Diagnostic Yield of Genetic Testing in Children Diagnosed With Autism Spectrum Disorders at a Regional Referral Center.   Clin Pediatr (Phila).

The aim was to systematically review genetic testing guidelines in the evaluation of children with autism spectrum disorders (ASDs). The Clinical Report published by the American Academy of Pediatrics (AAP)(1) recommended individualizing the workup, including karyotype and specific DNA testing for fragile X syndrome. A recent publication reported higher rates of abnormalities on CGH microarray (CMA) testing on children with ASD.(2) The medical records of 507 children seen through the Kirch ... [Abstract] [Full-text]

Early continuous inhibition of group 1 mGlu signaling partially rescues dendritic spine abnormalities in the Fmr1 knockout mouse model for fragile X syndrome.   Psychopharmacology (Berl), 215(2): 291-300.

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Articles on Fragile X Syndrome published 27 April 2011:

Memory Profiles of Down, Williams, and Fragile X Syndromes: Implications for Reading Development.   J Dev Behav Pediatr.

The purpose of this review was to understand the types of memory impairments that are associated with intellectual disability (ID, formerly called mental retardation) and the implications of these impairments for reading development. Specifically, studies on working memory, delayed memory and learning, and semantic/conceptual memory in Down syndrome, Williams syndrome, and fragile X syndrome were examined. A distinct memory profile emerged for each of the 3 etiologies of ID. Memory profiles are ... [Abstract] [Full-text]

Articles on Fragile X Syndrome published 26 April 2011:

Discrimination learning and attentional set formation in a mouse model of Fragile X.   Behav Neurosci.

Fragile X Syndrome is the most prevalent genetic cause of mental retardation. Selective deficits in executive function, including inhibitory control and attention, are core features of the disorder. In humans, Fragile X results from a trinucleotide repeat in the Fmr1 gene that renders it functionally silent and has been modeled in mice by targeted deletion of the Fmr1 gene. Fmr1 knockout (KO) mice recapitulate many features of Fragile X syndrome, but evidence for deficits in executive function ... [Abstract] [Full-text]

White matter changes in basis pontis in small expansion FMR1 allele carriers with parkinsonism.   Am J Med Genet B Neuropsychiatr Genet, 156(4): 502-6.

Examples of white matter hyperintensities (wmh) on magnetic resonance images in a basis pontis are presented in two male carriers, each of whom carry a small CGG expansion fragile X mental retardation (FMR1) allele. One carried a premutation (PM) allele of 85 CGG repeats and the other, a gray zone (GZ) allele of 47 repeats. Both were originally diagnosed with idiopathic Parkinson's disease (iPD). Similar changes are also shown in one PM carrier of 99 repeats affected with mild tremor and ... [Abstract] [Full-text]

Articles on Fragile X Syndrome published 25 April 2011:

Ablation of Fmrp in adult neural stem cells disrupts hippocampus-dependent learning.   Nat Med.

Deficiency in fragile X mental retardation protein (FMRP) results in fragile X syndrome (FXS), an inherited form of intellectual disability. Despite extensive research, it is unclear how FMRP deficiency contributes to the cognitive deficits in FXS. Fmrp-null mice show reduced adult hippocampal neurogenesis. As Fmrp is also enriched in mature neurons, we investigated the function of Fmrp expression in neural stem and progenitor cells (aNSCs) and its role in adult neurogenesis. Here we show that ... [Abstract] [Full-text]

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