Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0917816 (mental retardation)
 15,867 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The Rubinstein-Taybi syndrome (RTS) is a rare but well-defined condition characterized by growth and mental retardation, broad thumb-hallux, and distinctive facial features. Ten unrelated Taiwanese children (6 boys and 4 girls) with clinical features suggestive of RTS were evaluated. The associated anomalies included cryptochidism (6/6 males), microcephaly (9/10), congenital heart diseases (8/10), pectus excavatum (5/10), low IGF-I level (4/10), strabismus/nystagmus (4/10), epilepsy (3/10), glaucoma (2/10), cleft palate (2/10), web neck (2/10), limb hypoplasia (2/10), sleep apnea (1/10), and vesico-ureteral reflux (1/10). All of them had normal thyroid function. High-resolution chromosome studies by both G- and R-banding were applied to detect any microscopic chromosomal deletion, particularly over the 16p13 region (responsible for RTS locus). A panel of five cosmids spanning the human cyclic AMP-responsive element binding (CREB) binding protein (CREBBP or CBP) gene in terms of RT100, RT102, RT191, RT203 and RT166 (Leiden, the Netherlands) were used for fluorescence in situ hybridization on the metaphases of those patients. Three cases showed whole or partial deletion of one copy of the CBP gene. Thus, the rate for detecting interstitial submicroscopic deletion of this region by FISH was about 30% in these RTS patients. The disease severity seemed to be correlated with size of the deletion.
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PMID:Rubinstein-Taybi syndrome: clinical and molecular cytogenetic studies. 1623 61

FMR1 encodes an RNA-binding protein whose absence results in fragile X mental retardation. In most patients, the FMR1 gene is cytosine-methylated and transcriptionally inactive. NRF-1 and Sp1 are known to bind and stimulate the active, but not the methylated/silenced, FMR1 promoter. Prior analysis has implicated a CRE site in regulation of FMR1 in neural cells but the role of this site is controversial. We now show that a phospho-CREB/ATF family member is bound to this site in vivo. We also find that the histone acetyltransferases CBP and p300 are associated with active FMR1 but are lost at the hypoacetylated fragile X allele. Surprisingly, FMR1 is not cAMP-inducible and resides in a newly recognized subclass of CREB-regulated genes. We have also elucidated a role for NRF-2 as a regulator of FMR1 in vivo through a previously unrecognized and highly conserved recognition site in FMR1. NRF-1 and NRF-2 act additively while NRF-2 synergizes with CREB/ATF at FMR1's promoter. These data add FMR1 to the collection of genes controlled by both NRF-1 and NRF-2 and disfavor its membership in the immediate early response group of genes.
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PMID:The gene encoding the fragile X RNA-binding protein is controlled by nuclear respiratory factor 2 and the CREB family of transcription factors. 1650 Aug 91

Rubinstein-Taybi syndrome (RTS) is a rare human genetic disorder characterized by mental retardation and physical abnormalities. Many RTS patients have a genetic mutation which has been mapped to chromosome 16p13.3, a genomic region encoding cyclic AMP (cAMP) response element binding protein (CREB) binding protein (CBP). CBP is a transcriptional co-activator that binds to CREB when the latter is phosphorylated and promotes gene transcription. CREB-dependent gene transcription has been shown to underlie long-term memory formation. In this review we will focus on recent findings regarding the biology of CBP and its role in memory formation and cognitive dysfunction in RTS. We will also review the role of CBP in other neurological disorders, including Alzheimer's disease, Huntington's disease and amyotrophic lateral sclerosis. Finally, we will discuss novel therapeutic approaches targeted to CBP/CREB function for treating the cognitive dysfunction of RTS and other neurological disorders.
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PMID:Rubinstein-Taybi syndrome: molecular findings and therapeutic approaches to improve cognitive dysfunction. 1678 26

Major recent advances in the field of chromatin remodeling have dramatically changed our understanding of the ways in which genes are regulated. Epigenetic regulators such as histone deacetylases (HDACs) and histone acetyltransferases (HATs) are increasingly being implicated as direct or indirect components in the regulation of expression of neuronal, immune and other tissue specific genes. HDACs and HATs have been shown to play important roles in cell growth, cell cycle control, development, differentiation and survival. Mutations in genes that encode HDAC-binding proteins cause neurological disorders, such as MeCP2 mutations in Rett's syndrome. Mutations of CBP, a gene with HAT function, cause the mental retardation-associated Rubinstein-Taybi syndrome. Recently, HDAC inhibitors have been found to ameliorate progression of the spinal muscular atrophy (SMA) motor neuron disease and the Huntington disease mouse models. The neuroprotective role of HDAC inhibitors seems to extend to other diseases that share mechanisms of oxidative stress, inflammation and neuronal cell apoptosis. HDAC inhibitors also have widespread modulatory effects on gene expression within the immune system and have been used successfully in the lupus and rheumatoid arthritis autoimmune disease models. Recently, we demonstrated the efficacy of the HDAC inhibitor Trichostatin A in ameliorating disease in the multiple sclerosis (MS) animal model, experimental autoimmune encephalomyelitis (EAE). In this review we describe the current literature surrounding these inhibitors and propose a rationale for harnessing both their neuroprotective and anti-inflammatory effects to treat MS, an autoimmune, demyelinating and degenerative disease of the human central nervous system (CNS).
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PMID:Rationale for the use of histone deacetylase inhibitors as a dual therapeutic modality in multiple sclerosis. 1799 7

We report on a 16-year-old girl with a multiple congenital anomalies/mental retardation condition, in which a 1.7 Mb tandem duplication of chromosome region 16p13.3 was detected by array-CGH. Mental retardation was moderate (IQ 45), with very limited speech. She had tall stature with relative microcephaly. Clinical manifestations included distinctive facial appearance with deep set eyes, narrow palpebral fissures, wide nasal bridge, long philtrum, rounded nasal tip, thin upper lip, protruding mandible and abnormal auricles, hand and foot anomalies. The causal 16p13.3 duplication is one of the smallest reported so far, and includes the CBP gene, whose haploinsufficiency is responsible for the Rubinstein-Taybi syndrome. By comparing clinical manifestations of our patient with those of patients carrying similar rearrangements, we could infer that 16p13.3 microduplications encompassing the Rubinstein-Taybi region result in a recognizable clinical condition, most likely representing a single gene disorder.
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PMID:Duplication of the Rubinstein-Taybi region on 16p13.3 is associated with a distinctive phenotype. 1868 73

X-linked alpha-thalassemia/mental retardation syndrome (ATR-X syndrome, OMIM #301040) is one of the syndromes associated with abnormal epigenetic gene regulation, including ICF(DNMT3B), Rett (MECP2), Rubinstein-Taybi (CBP), Coffin-Lowry (RSK2), and Sotos (NSD1) syndromes. It is a syndromic form of X-linked mental retardation, which affects males and is characterized by profound mental retardation, mild HbH disease (alpha-thalassemia), facial dysmorphism, skeletal abnormalities, and autistic behavior. ATR-X syndrome is caused by a mutation in the ATRX gene on the X chromosome (Xq13), which encodes ATRX protein, belonging to the SNF2 family of chromatin-remodeling proteins. The protein has two functionally important domains: an ADD (ATRX-DNMT3-DNMT3L) domain at the N-terminus, and chromatin-remodeling domain in the C-terminal half, where the ATRX gene mutations of most ATR-X patients reside. Perturbation in DNA methylation in the rDNA genes was repored in ATR-X patients, and ATRX protein is presumed to be involved in the establishment and maintenance of DNA methylation. Based on its various clinical phenotypes, the expressions of many genes, including alpha globin genes, seem to be abnormally regulated in ATR-X patients. However, the precise mechanism involving ATRX protein remains to be elucidated. Epigenetics can link environmental and genetic causes of many pathological conditions. The genes, which are abnormally regulated by a perturbed epigenetic mechanism, are, in themselves, structurally normal, and the elucidation of their mechanism may lead to the development of appropriate therapy.
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PMID:[X-linked alpha-thalassemia/mental retardation syndrome]. 1948 41

Sizn1 (Zcchc12) is a transcriptional co-activator that positively modulates bone morphogenic protein (BMP) signaling through its interaction with Smad family members and CBP. We have demonstrated a role for Sizn1 in basal forebrain cholinergic neuron specific gene expression. Furthermore, mutations in SIZN1 have been associated with X-linked mental retardation. Given the defined role of SIZN1 in mental retardation, knowing its complete forebrain expression pattern is essential to further elucidating its role in cognition. To better define the dynamic expression pattern of Sizn1 during forebrain development, we investigated its expression in mouse brain development from embryonic day 8.0 (E8.0) to adult. We found that Sizn1 is primarily restricted to the ventral forebrain including the medial ganglionic eminence, the septum, amygdala, and striatum. In addition, Sizn1 expression is detected in the cortical hem and pallial-subpallial boundary (PSB; anti-hem); both sources of Cajal-Retzius cells. Sizn1 expression in the dorsal forebrain is restricted to a subset of cells in the marginal zone that also express Reln, indicative of Cajal-Retzius cells. These data provide novel information on brain regions and cell types that express Sizn1, facilitating further investigations into the function of Sizn1 in both development and the pathogenesis of mental retardation.
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PMID:XLMR candidate mouse gene, Zcchc12 (Sizn1) is a novel marker of Cajal-Retzius cells. 2117 56

Rubinstein-Taybi syndrome (RTS) is an incurable genetic disorder with combination of mental retardation and physical features including broad thumbs and toes, craniofacial abnormalities, and growth deficiency. While the autosomal dominant mode of transmission is limitedly known, the majority of cases are attributable to de novo mutations in RTS. The first identified gene associated with RTS is CREB-binding protein (CREBBP/CBP). Alterations of the epigenetic 'histone code' due to dysfunction of the CBP histone acetyltransferase activity deregulate gene transcriptions that are prominently linked to RTS pathogenesis. In this review, we discuss how CBP mutation contributes to modifications of histone and how histone deacetylase inhibitors are therapeutically applicable to epigenetic conditioning in RTS. Since most genetic mutations are irreversible and therapeutic approaches are limited, therapeutic targeting of reversible epigenetic components altered in RTS may be an ideal strategy. Expeditious further study on the role of the epigenetic mechanisms in RTS is encouraged to identify novel epigenetic markers and therapeutic targets to treat RTS.
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PMID:Epigenetic mechanisms of Rubinstein-Taybi syndrome. 2438 Nov 14

TSPYL2 is an X-linked gene encoding a nucleosome assembly protein. TSPYL2 interacts with calmodulin-associated serine/threonine kinase, which is implicated in X-linked mental retardation. As nucleosome assembly and chromatin remodeling are important in transcriptional regulation and neuronal function, we addressed the importance of TSPYL2 through analyzing Tspyl2 loss-of-function mice. We detected down-regulation of N-methyl-D-aspartate receptor subunits 2A and 2B (GluN2A and GluN2B) in the mutant hippocampus. Evidence from luciferase reporter assays and chromatin immunoprecipitation supported that TSPYL2 regulated the expression of Grin2a and Grin2b, the genes encoding GluN2A and GluN2B. We also detected an interaction between TSPYL2 and CBP, indicating that TSPYL2 may activate gene expression through binding CBP. In terms of functional outcome, Tspyl2 loss-of-function impaired long-term potentiation at hippocampal Schaffer collateral-CA1 synapses. Moreover, mutant mice showed a deficit in fear learning and memory. We conclude that TSPYL2 contributes to cognitive variability through regulating the expression of Grin2a and Grin2b.
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PMID:The nucleosome assembly protein TSPYL2 regulates the expression of NMDA receptor subunits GluN2A and GluN2B. 2441 69

DYRK1A, dual-specificity tyrosine phosphorylation-regulated kinase 1A, which is linked to mental retardation and microcephaly, is a member of the CMGC group of kinases. It has both cytoplasmic and nuclear functions, however, molecular mechanisms of how DYRK1A regulates gene expression is not well understood. Here, we identify two histone acetyltransferases, p300 and CBP, as interaction partners of DYRK1A through a proteomics study. We show that overexpression of DYKR1A causes hyperphosphorylation of p300 and CBP. Using genome-wide location (ChIP-sequencing) analysis of DYRK1A, we show that most of the DYRK1A peaks co-localize with p300 and CBP, at enhancers or near the transcription start sites (TSS). Modulation of DYRK1A, by shRNA mediated reduction or transfection mediated overexpression, leads to alteration of expression of downstream located genes. We show that the knockdown of DYRK1A results in a significant loss of H3K27acetylation at these enhancers, suggesting that DYRK1A modulates the activity of p300/CBP at these enhancers. We propose that DYRK1A functions in enhancer regulation by interacting with p300/CBP and modulating their activity. Overall, DYRK1A function in the regulation of enhancer activity provides a new mechanistic understanding of DYRK1A mediated regulation of gene expression, which may help in better understanding of the roles of DYRK1A in human pathologies.
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PMID:DYRK1A interacts with histone acetyl transferase p300 and CBP and localizes to enhancers. 3013 13


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