Read by QxMD icon Read


Nina Xie, He Gong, Joshua A Suhl, Pankaj Chopra, Tao Wang, Stephen T Warren
Fragile X syndrome (FXS) is a common cause of intellectual disability that is most often due to a CGG-repeat expansion mutation in the FMR1 gene that triggers epigenetic gene silencing. Epigenetic modifying drugs can only transiently and modestly induce FMR1 reactivation in the presence of the elongated CGG repeat. As a proof-of-principle, we excised the expanded CGG-repeat in both somatic cell hybrids containing the human fragile X chromosome and human FXS iPS cells using the CRISPR/Cas9 genome editing. We observed transcriptional reactivation in approximately 67% of the CRISPR cut hybrid colonies and in 20% of isolated human FXS iPSC colonies...
2016: PloS One
Amy Krans, Michael G Kearse, Peter K Todd
OBJECTIVE: Repeat associated non-AUG (RAN) translation drives production of toxic proteins from pathogenic repeat sequences in multiple untreatable neurodegenerative disorders. Fragile X-associated tremor/ataxia syndrome (FXTAS) is one such condition, resulting from a CGG trinucleotide repeat expansion in the 5' leader sequence of the FMR1 gene. RAN proteins from the CGG repeat accumulate in ubiquitinated inclusions in FXTAS patient brains and elicit toxicity. In addition to the CGG repeat, an antisense mRNA containing a CCG repeat is also transcribed from the FMR1 locus...
October 19, 2016: Annals of Neurology
Indhu-Shree Rajan-Babu, Samuel S Chong
Fragile X syndrome (FXS) is the most common monogenic cause of intellectual disability and autism. Molecular diagnostic testing of FXS and related disorders (fragile X-associated primary ovarian insufficiency (FXPOI) and fragile X-associated tremor/ataxia syndrome (FXTAS)) relies on a combination of polymerase chain reaction (PCR) and Southern blot (SB) for the fragile X mental retardation 1 (FMR1) CGG-repeat expansion and methylation analyses. Recent advancements in PCR-based technologies have enabled the characterization of the complete spectrum of CGG-repeat mutation, with or without methylation assessment, and, as a result, have reduced our reliance on the labor- and time-intensive SB, which is the gold standard FXS diagnostic test...
October 14, 2016: Genes
Jeremy Veenstra-VanderWeele, Edwin H Cook, Bryan H King, Peter Zarevics, Maryann Cherubini, Karen Walton-Bowen, Mark F Bear, Paul P Wang, Randall L Carpenter
Several lines of emerging data point to an imbalance between neuronal excitation and inhibition in at least a subgroup of individuals with autism spectrum disorder (ASD), including in those with fragile X syndrome (FXS), one of the most common genetic syndromes within ASD. In animal models of FXS and of ASD, GABA-B agonists have improved both brain and behavioral phenotypes, including social behavior. A phase 2 randomized, placebo-controlled, crossover trial found that the GABA-B agonist arbaclofen improved social avoidance symptoms in FXS...
October 17, 2016: Neuropsychopharmacology: Official Publication of the American College of Neuropsychopharmacology
Cyrus Vahdatpour, Adam H Dyer, Daniela Tropea
Insulin-Like Growth Factor 1 (IGF-1) is a neurotrophic polypeptide with crucial roles to play in Central Nervous System (CNS) growth, development and maturation. Following interrogation of the neurobiology underlying several neurodevelopmental disorders and Autism Spectrum Disorders (ASD), both recombinant IGF-1 (mecasermin) and related derivatives, such as (1-3)IGF-1, have emerged as potential therapeutic approaches. Clinical pilot studies and early reports have supported the safety/preliminary efficacy of IGF-1 and related compounds in the treatment of Rett Syndrome, with evidence mounting for its use in Phelan McDermid Syndrome and Fragile X Syndrome...
2016: Frontiers in Neuroscience
Annie L Shelton, Kim Cornish, Meaghan Clough, Sanuji Gajamange, Scott Kolbe, Joanne Fielding
Executive dysfunction has been demonstrated among premutation (PM) carriers (55-199 CGG repeats) of the Fragile X mental retardation 1 (FMR1) gene. Further, alterations to neural activation patterns have been reported during memory and comparison based functional magnetic resonance imaging (fMRI) tasks in these carriers. For the first time, the relationships between fMRI neural activation during an interleaved ocular motor prosaccade/antisaccade paradigm, and concurrent task performance (saccade measures of latency, accuracy and error rate) in PM females were examined...
October 14, 2016: Human Brain Mapping
S Hossein Fatemi, Timothy D Folsom, Stephanie B Liesch, Rachel E Kneeland, Mahtab Karkhane Yousefi, Paul D Thuras
Prenatal viral infection has been identified as a potential risk factor for the development of neurodevelopmental disorders such as schizophrenia and autism. Additionally, dysfunction in gamma-aminobutyric acid, Reelin, and fragile X mental retardation protein (FMRP)-metabotropic glutamate receptor 5 signaling systems has also been demonstrated in these two disorders. In the current report, we have characterized the developmental profiles of selected markers for these systems in cerebella of mice born to pregnant mice infected with human influenza (H1N1) virus on embryonic day 16 or sham-infected controls using SDS-PAGE and Western blotting techniques and evaluated the presence of abnormalities in the above-mentioned markers during brain development...
October 13, 2016: Journal of Neuroscience Research
S S Hall, R P Barnett, K M Hustyi
BACKGROUND: A large proportion of boys with fragile X syndrome (FXS), the most common known inherited form of intellectual disability (ID), exhibit problem behaviours (e.g. aggression, self-injury, property destruction and stereotypy) that can negatively impact the health and safety of others as well as the individual concerned. However, data are limited concerning the relative prevalence, frequency and severity of problem behaviours exhibited by boys with FXS compared with those by boys with mixed-aetiology ID who also exhibit problem behaviours...
October 11, 2016: Journal of Intellectual Disability Research: JIDR
Ping Lu, Xiaolong Chen, Yun Feng, Qiao Zeng, Cizhong Jiang, Xianmin Zhu, Guoping Fan, Zhigang Xue
Fragile X syndrome (FXS) patients carry the expansion of over 200 CGG repeats at the promoter of fragile X mental retardation 1 (FMR1), leading to decreased or absent expression of its encoded fragile X mental retardation protein (FMRP). However, the global transcriptional alteration by FMRP deficiency has not been well characterized at single nucleotide resolution, i.e., RNA-seq. Here, we performed in-vitro neuronal differentiation of human induced pluripotent stem (iPS) cells that were derived from fibroblasts of a FXS patient (FXS-iPSC)...
October 11, 2016: Science China. Life Sciences
Rebecca Lyndsey Hardiman, Alison Bratt
Fragile X Syndrome (FXS) is characterised by features including anxiety and autistic-like behaviour, which led to early hypotheses that aberrant physiological arousal may underlie the behavioural phenotype. In line with this, several lines of evidence suggest that the hypothalamic-pituitary-adrenal (HPA) axis may be altered in the syndrome. This review collates evidence to determine the nature of HPA axis baseline activity and reactivity (as measured by glucocorticoid levels) differences in FXS, and its relationship to behaviour...
October 5, 2016: Physiology & Behavior
Ramona Alfaro Arenas, Jordi Rosell Andreo, Damián Heine Suñer
We report herein results of a study performed in the Balearic Islands which had the following goals: 1) Determine the proportion of pregnant or non-pregnant women planning pregnancy, who would choose to undergo a screening test for Fragile X Syndrome (FXS), if it is accompanied by the appropriate information; 2) Assess satisfaction and any increase in stress among women who participate in screening; 3) Collect epidemiological information about the incidence of the disease in our population; and 4) Collect demographic and health history data and assess participants' awareness of the disease...
October 7, 2016: Journal of Genetic Counseling
Yifan Zhou, Daman Kumari, Nicholas Sciascia, Karen Usdin
BACKGROUND: Fragile X syndrome (FXS), a common cause of intellectual disability and autism, results from the expansion of a CGG-repeat tract in the 5' untranslated region of the FMR1 gene to >200 repeats. Such expanded alleles, known as full mutation (FM) alleles, are epigenetically silenced in differentiated cells thus resulting in the loss of FMRP, a protein important for learning and memory. The timing of repeat expansion and FMR1 gene silencing is controversial. METHODS: We monitored the repeat size and methylation status of FMR1 alleles with expanded CGG repeats in patient-derived induced pluripotent stem cells (iPSCs) and embryonic stem cells (ESCs) that were grown for extended period of time either as stem cells or differentiated into neurons...
2016: Molecular Autism
Chul-Yong Park, Jin Jea Sung, Sang-Hwi Choi, Dongjin R Lee, In-Hyun Park, Dong-Wook Kim
Genome engineering technology using engineered nucleases has been rapidly developing, enabling the efficient correction of simple mutations. However, the precise correction of structural variations (SVs) such as large inversions remains limited. Here we describe a detailed procedure for the modeling or correction of large chromosomal rearrangements and short nucleotide repeat expansions using engineered nucleases in human induced pluripotent stem cells (hiPSCs) from a healthy donor and patients with SVs. This protocol includes the delivery of engineered nucleases with no donor template to hiPSCs, and genotyping and derivation/characterization of gene-manipulated hiPSC clones...
November 2016: Nature Protocols
Xiao Wang, Yawen Mu, Mengshi Sun, Junhai Han
Homeostatic regulation of the light sensor, rhodopsin, is critical for the maintenance of light sensitivity and survival of photoreceptors. The major fly rhodopsin, Rh1, undergoes light-induced endocytosis and degradation, but its protein and mRNA levels remain constant during light/dark cycles. It is not clear how translation of Rh1 is regulated. Here, we show that adult photoreceptors maintain a constant, abundant quantity of ninaE mRNA, which encodes Rh1. We demonstrate that the Fmr1 protein associates with ninaE mRNA and represses its translation...
October 4, 2016: Journal of Molecular Cell Biology
Clara D M van Karnebeek, Kristin Bowden, Elizabeth Berry-Kravis
BACKGROUND: Neurogenetic developmental conditions represent a heterogeneous group of rare inherited disorders with neurological manifestation during development. Treatments for these conditions have largely been supportive; however, a number of treatments are emerging which target the underlying physiology and offer great potential. Our aim was to present a state-of-the-art overview of the current and potential causal treatments available or under development for neurogenetic developmental conditions...
July 26, 2016: Pediatric Neurology
Yun Tae Hwang, Solange Mabel Aliaga, Marta Arpone, David Francis, Xin Li, Belinda Chong, Howard Robert Slater, Carolyn Rogers, Lesley Bretherton, Matthew Hunter, Robert Heard, David Eugeny Godler
CGG repeat expansion >200 within FMR1, termed full mutation (FM), has been associated with promoter methylation, consequent silencing of gene expression and fragile X syndrome (FXS)-a common cause of intellectual disability and co-morbid autism. Unmethylated premutation (55-199 repeats) and FM alleles have been associated with fragile X related tremor/ataxia syndrome (FXTAS), a late onset neurodegenerative disorder. Here we present a 33-year-old male with FXS, with white matter changes and progressive deterioration in gait with cerebellar signs consistent with probable FXTAS; there was no evidence of any other cerebellar pathology...
October 1, 2016: American Journal of Medical Genetics. Part A
Atefeh Entezari, Mahmoud Shekari Khaniani, Tayyeb Bahrami, Sima Mansoori Derakhshan, Hossein Darvish
Male carriers of an expansion of CGG alleles (with 55-200 CGG repeats) in the FMR1 gene are affected with Fragile X-associated tremor/ataxia syndrome (FXTAS). On the other hand, individuals with Parkinson's disease (PD) or Parkinsonism spectrum disorders may have some clinical features that overlap with FXTAS. To investigate the possible association between PD and FMR1 expanded alleles, we screened a total of 154 male PD patients and 190 gender- and age-matched healthy control subjects from Iran. Eleven intermediate allele carriers (7...
October 1, 2016: Neurological Sciences
Roseanne Rosario, Panagiotis Filis, Victoria Tessyman, Hazel Kinnell, Andrew J Childs, Nicola K Gray, Richard A Anderson
Germ cell development and primordial follicle formation during fetal life is critical in establishing the pool of oocytes that subsequently determines the reproductive lifespan of women. Fragile X-associated primary ovarian insufficiency (FXPOI) is caused by inheritance of the FMR1 premutation allele and approximately 20% of women with the premutation allele develop ovarian dysfunction and premature ovarian insufficiency. However, the underlying disease mechanism remains obscure, and a potential role of FMRP in human ovarian development has not been explored...
2016: PloS One
Hagar Mor-Shaked, Rachel Eiges
Fragile X syndrome (FXS) is the most common heritable form of cognitive impairment. It results from a loss-of-function mutation by a CGG repeat expansion at the 5' untranslated region of the X-linked fragile X mental retardation 1 (FMR1) gene. Expansion of the CGG repeats beyond 200 copies results in protein deficiency by leading to aberrant methylation of the FMR1 promoter and the switch from active to repressive histone modifications. Additionally, the CGGs become increasingly unstable, resulting in high degree of variation in expansion size between and within tissues of affected individuals...
2016: Genes
Randall Michael Golovin, Kendal Broadie
Evidence accumulating over the past 15 years refutes the dogma that the Drosophila nervous system is hardwired. The preponderance of studies reveals activity-dependent neural circuit refinement driving the optimization of behavioral outputs. Here, we describe developmental, sensory input-dependent plasticity in the brain olfactory antennal lobe that we term long-term central adaption (LTCA). LTCA is evoked by prolonged exposure to an odorant during the first week of post-eclosion life, resulting in a persistent decreased response to aversive odors and enhanced response to attractive odors...
September 28, 2016: Journal of Neurophysiology
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"