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)

Rubinstein-Taybi syndrome (RSTS) is a well-known autosomal dominant mental retardation syndrome with typical facial and skeletal abnormalities. Previously, we have reported two patients presenting with RSTS and additional clinical features including failure to thrive, seizures, and intractable infections (Bartsch et al. in Eur J Hum Genet 7:748-756, 1999). Recently we identified a third patient with this condition, termed here severe RSTS, or chromosome 16p13.3 deletion syndrome. The three patients died in infancy, and all displayed a specific mutation, a chromosomal microdeletion including the 3'-end of the CREBBP gene. Using fluorescence in situ hybridization and closely spaced DNA probes, we characterized the deletion intervals in these patients and in three individuals with a deletion of CREBBP and typical RSTS. The deleted DNA segments were found to greatly vary in size, spanning from approximately 40 kb to >3 Mb. Four individuals, including the patients with severe RSTS, exhibited deletions containing gene/s in addition to CREBBP. The patients with severe RSTS all had deletions comprising telomeric neighbor genes of CREBBP, including DNASE1, a dominant gene encoding a nuclease that has been associated with systemic lupus erythematodes. Our findings suggest that severe RSTS is distinct from RSTS and represents a novel true contiguous gene syndrome (chromosome 16p13.3 deletion syndrome). Because of the risk of critical infections and high mortality rate, we recommend that the size of the deletion interval should be determined in CREBBP deletion-positive patients with RSTS, especially in young children. Further studies are needed to delineate the clinical spectrum of the new disorder and to clarify the role of DNASE1.
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PMID:Evidence for a new contiguous gene syndrome, the chromosome 16p13.3 deletion syndrome alias severe Rubinstein-Taybi syndrome. 1678 66

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

Rubinstein-Taybi syndrome (RTS) is characterized by typical facies, short stature, mental retardation, broad thumbs and broad great toes. The syndrome is at least in part caused by microdeletions at chromosome 16p13.3 or by mutations in the gene for the CREB binding protein (CBP), which is located at 16p13.3. Familial Mediterranean fever (FMF) is an autosomal recessive disease, caused by mutations in the FMF-gene [Mediterranean fever (MEFV)] and characterized by recurrent attacks of fever and peritonitis, arthritis and pleuritis. The FMF gene (MEFV) has recently been cloned by two consortia and 30 point mutations, causing the disease have been identified. MEFV maps to chromosome 16p and encodes a 781-amino-acid protein called pyrin or marenostrin, which is expressed mainly in neutrophils and myeloid bone marrow precursors. Herein, we report a case with RTS and FMF.
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PMID:Rubinstein-Taybi syndrome and familial Mediterranean fever in a single patient: two distinct genetic diseases located on chromosome 16p13.3. 1705 63

This chapter explores some of the molecular events contributing to memory formation and how, when these events malfunction, disturbances in memory occur. After a brief discussion of signaling in the hippocampus, we will explore the topics of human mental retardation syndromes that involve disruption of these processes, including Angelman syndrome (AS), Neurofibromatosis 1 (NF1)-associated learning disorders, Coffin-Lowry syndrome (CLS), Rubinstein-Taybi syndrome (RTS), and Rett syndrome (RTT).
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PMID:Signal transduction mechanisms in memory disorders. 1716 2

The Rubinstein-Taybi syndrome (RSTS, MIM 180849), a dominant Mendelian disorder with typical face, short stature, skeletal abnormalities, and mental retardation, is usually caused by heterozygous mutations of the CREBBP gene, but recently, EP300 gene mutations were reported in three individuals. Using quantitative PCR (for the CREBBP and EP300 genes) and genomic sequencing (for the EP300 gene), we studied here 13 patients who had shown no mutation after genomic sequencing of the CREBBP gene in a previous investigation. Two new disease-causing mutations were identified, including a partial deletion of CREBBP and a 1-bp deletion in EP300, c.7100delC (p.P2366fsX2401). The 1-bp deletion represents the fourth EP300 mutation reported to date and was identified in a patient with non-classical RSTS. Based on the very similar structure of the CREBBP and EP300 genes and the higher rate of single-nucleotide polymorphisms in EP300 (2.23 per individual) as compared to CREBBP (0.71 per individual) (P>0.001, Wilcoxon test), it may be assumed that EP300 gene mutations should be as frequent as CREBBP gene mutations. Based on the location of the EP300 gene mutations identified so far (outside the histone acetyl transferase domain) and the observed (although not very striking) phenotypical differences with the EP300 mutations, we propose that most EP300 mutations could be associated with other phenotypes, not classical RSTS.
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PMID:Confirmation of EP300 gene mutations as a rare cause of Rubinstein-Taybi syndrome. 1729 36

Rubinstein-Taybi syndrome is characterised by mental retardation, growth retardation and a particular dysmorphology. The syndrome is rare, with a frequency of approximately one affected individual in 100,000 newborns. Mutations in two genes - CREBBP and EP300 - have been identified to cause the syndrome. These two genes show strong homology and encode histone acetyltransferases (HATs), which are transcriptional co-activators involved in many signalling pathways. Loss of HAT activity is sufficient to account for the phenomena seen in Rubinstein-Taybi patients. Although some mutations found in CREBBP are translocations, inversions and large deletions, most are point mutations or small deletions and insertions. Mutations in EP300 are comparatively rare. Extensive screening of patients has revealed mutations in CREBBP and EP300 in around 50% of cases. The cause of the syndrome in the remaining patients remains to be identified, but other genes could also be involved. Here, we describe the clinical presentation of Rubinstein-Taybi syndrome, review the mutation spectrum and discuss the current understanding of causative molecular mechanisms.
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PMID:Rubinstein-Taybi syndrome: clinical and molecular overview. 1794 8

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

Rubinstein-Taybi syndrome (RTS) is a rare multiple congenital anomaly/intellectual impairment syndrome. Loss of function in CREBBP or EP300 genes has been found in about 50% of patients with RTS. Genotype-phenotype correlations were investigated in 93 patients meeting diagnostic criteria for RTS during 2 international RTS family conferences. Mutation analysis of CREBBP was performed on all 31 coding exons and exon-intron junctions; a subset of patients had FISH analysis for large deletions. A total of 64 different variations were observed in the DNA sequence, and determined to be definitive mutations in 52 patients (56%). Mutations detected included: 10 missense mutations; 36 truncating or splice-site mutations; and 6 large deletions detectable by FISH. Fourteen patients had synonymous changes of unknown significance. The majority of mutations affected the HAT domain of CREBBP or predicted termination of the protein before the HAT region. Extensive phenotypic data were collected on each patient and analyzed to determine correlations with mutation types, that is, truncating, large deletions, single amino acid substitutions, or no CREBBP mutation. All four groups displayed the characteristic facial and thumb dysmorphology. Growth retardation in height and weight was seen more frequently in patients with no CREBBP mutation; seizure disorder was more frequent in those with CREBBP mutations. Degree of mental retardation was similar in all groups, although there was a trend toward lower IQ and autistic features in patients with large deletions. Similarity in phenotype between the groups implies that the several genes involved in causing RTS likely have effects through the same pathway.
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PMID:Genotype-phenotype correlations in Rubinstein-Taybi syndrome. 1879 86

A child with Rubinstein-Taybi syndrome was diagnosed at birth with contraction of the left knee in flexion. A sonography of both knees, performed at 4 months of age, resulted in diagnosing a laterally displaced, hypoplastic left patella. Surgery was performed at 8 months of age as described by Stanisavljevic, which resulted in correct alignment of the patella. Follow-up examination at 2.5 years of age showed a contracture in flexion of 10 degrees , passively redressible with application of gentle force and clinically correct alignment of the patella. Sonography showed the left patella to be similar in size, shape, and position to the right patella. The child still did not walk because of mental retardation, but stood upright unsupported. Stanisavljevic procedure in this case gave good results. Sonography gives excellent view of the unossified patella, as well as other nearby soft tissues, and is sufficient for a correct diagnosis.
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PMID:Congenital patella dislocation in a child with Rubinstein-Taybi syndrome. 1943 46


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