Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0025362 (mental retardation)
 15,878 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Two novel members of the interleukin-1 receptor (IL-1R) family, identified by homology searches of human genomic sequence data bases, are described. The genes have been named according to their structural features: TIGIRR-1 (three immunoglobulin domain-containing IL-1 receptor-related) and TIGIRR-2. TIGIRR-2 has recently been identified as causing mental retardation when mutated (Carrie, A., Jun, L., Bienvenu, T., Vinet, M. C., McDonell, N., Couvert, P., Zemni, R., Cardona, A., Van Buggenhout, G., Frints, S., Hamel, B., Moraine, C., Ropers, H. H., Strom, T., Howell, G. R., Whittaker, A., Ross, M. T., Kahn, A., Fryns, J. P., Beldjord, C., Marynen, P., and Chelly, J. (1999) Nat. Genet. 23, 25-31) and called IL1RAPL, a name we will also use henceforth. Neither receptor alone was able to mediate transcriptional activation of NF-kappaB in response to IL-1alpha, IL-1beta, or IL-18. In order to begin to elucidate the function of these and other orphan IL-1R family members, we have developed a functional assay utilizing a panel of chimeric receptors containing the extracellular and transmembrane domains of either type I IL-1R or IL-1R accessory protein (AcP) coupled to the cytoplasmic domains of all family members. Coexpression of each IL-1R chimera with each AcP chimera and an NF-kappaB-responsive reporter demonstrated that the cytoplasmic domains could be classified as IL-1R-like, AcP-like, or neither. Any IL-1R-like cytoplasmic domain could cooperate with any AcP-like cytoplasmic domain. The TIGIRR-1 and IL1RAPL cytoplasmic domains, however, were unable to signal as either IL-1R-like or AcP-like components, suggesting that they function as a new class of receptors within this family.
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PMID:Identification and characterization of two members of a novel class of the interleukin-1 receptor (IL-1R) family. Delineation of a new class of IL-1R-related proteins based on signaling. 1088 29

X-linked forms of mental retardation (XLMR) include a variety of different disorders and may account for up to 25% of all inherited cases of mental retardation. So far, seven X-chromosomal genes mutated in nonspecific mental retardation (MRX) have been identified: FMR2, GDI1, RPS6KA3, IL1RAPL, TM4SF2, OPHN1 and PAK3 (refs 2-9). The products of the latter two have been implicated in regulation of neural plasticity by controlling the activity of small GTPases of the Rho family. Here we report the identification of a new MRX gene, ARHGEF6 (also known as alphaPIX or Cool-2), encoding a protein with homology to guanine nucleotide exchange factors for Rho GTPases (Rho GEF). Molecular analysis of a reciprocal X/21 translocation in a male with mental retardation showed that this gene in Xq26 was disrupted by the rearrangement. Mutation screening of 119 patients with nonspecific mental retardation revealed a mutation in the first intron of ARHGEF6 (IVS1-11T-->C) in all affected males in a large Dutch family. The mutation resulted in preferential skipping of exon 2, predicting a protein lacking 28 amino acids. ARHGEF6 is the eighth MRX gene identified so far and the third such gene to encode a protein that interacts with Rho GTPases.
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PMID:Mutations in ARHGEF6, encoding a guanine nucleotide exchange factor for Rho GTPases, in patients with X-linked mental retardation. 1101 88

The Interleukin-1 receptor (IL-1R) and Toll signaling pathways share the evolutionarily conserved Toll homology domain (THD), which is a critical component in the signaling cascade of the host defense responses to infection and inflammation. Our initial genomic database searches uncovered a novel THD signature sequence between DNA markers DXS87 and DXS366. The feasibility of subsequently applying a coordinated computational approach, including various exon-finding programs, homology-based searches, and receptor profile searches, in revealing the exons encoding this novel IL-1R family member is described. IL-1R9 shows restricted expression in fetal brain and is highly homologous to IL1RAPL (A. Carrie et al., 1999 Nat. Genet. 23: 25-31), which is reportedly involved in nonsyndromic X-linked mental retardation. These genes are scattered over separate genomic intervals in excess of 1.0 Mb and encode receptors with extended C-terminal tails. In our functional NF-kappaB reporter assays, IL1RAPL, IL-1R9, or versions lacking the extended C-terminal sequences failed in responding either to IL-1 directly or to IL-18 when various permutations of IL-18R ectodomain chimeras were fused to their cytoplasmic domains. Evolutionary sequence analyses reinforce our conclusion that these novel orphan receptors probably form a functionally distinct subset of the IL-1R superfamily.
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PMID:Computational identification, cloning, and characterization of IL-1R9, a novel interleukin-1 receptor-like gene encoded over an unusually large interval of human chromosome Xq22.2-q22.3. 1103 Nov 8

Mental retardation (MR) is a group of heterogeneous clinical conditions. There are more than 900 genetic disorders associated with MR and it affects around 3% of the general population. MR can be subdivided into syndromic, if it is characterized by consistent and distinctive clinical findings, and nonspecific, if mental retardation is the only primary symptom among affected individuals. Many MR conditions described are syndromic, fragile X syndrome being the most common clinical entity among them. In the past years, knowledge of the molecular basis of mental retardation has increased remarkably. Eight genes involved in nonspecific X-linked MR have been identified so far, including FMR2, OPHN1, GDI1, PAK3, IL1RAPL, TM4SF2, VCX-A, and ARHGEF6. Two other genes also located on the X chromosome have been involved both in syndromic and in MRX forms (RSK2 and XNP/ATR-X). New insights into the pathogenesis of mental retardation are being provided by the discovery of these genes involved in different cellular signaling pathways in the central nervous system although many others remain to be identified.
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PMID:Genes responsible for nonspecific mental retardation. 1116 35

We report the identification and characterization of a homologue of the IL1RAPL transcript which is responsible for a form of X-linked mental retardation (MRX34). This new transcript was cloned by analysis of genomic sequences from the Xq22 region and was named IL1RAPL2 (Interleukin 1 Receptor Accessory Protein-Like-2). The two X-linked genes share the same domains, the same exon-intron organization and a high degree of similarity at the protein level (70.4% similarity). RNA in situ expression studies on mouse embryo tissue section at different developmental stages show that Il1rapl2 is specifically expressed in the nervous system from embryonic day 12.5. The homologies together with the pattern of expression render ILRAPL2 a candidate gene for disorders displaying involvement of the CNS, including the MRX loci for which the gene has not been identified yet.
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PMID:IL1RAPL2 maps to Xq22 and is specifically expressed in the central nervous system. 1158 48

X-linked forms of non-specific mental retardation are complex disorders, for which mutations in several genes have recently been identified. These include OPHN1, GDI1, PAK3, IL1RAPL, TM4SF2, FMR2 and RSK2. To investigate the mechanisms through which alterations of these gene products could result in cognitive impairment, we analyzed their expression using quantitative PCR technique in two in vitro models of activity-dependent gene regulation: kainate-induced seizures and long-term synaptic potentiation (LTP). We found that the level of expression of four genes, PAK3, IL1RAPL, RSK2 and TM4SF2, was significantly up-regulated following kainate treatment. Furthermore we observed a significant increase in mRNA levels of PAK3 and IL1RAPL following LTP induction. These results suggest a possible role for these four genes in activity-dependent brain plasticity.
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PMID:Activity-dependent regulation of genes implicated in X-linked non-specific mental retardation. 1220 50

Physical mapping of the breakpoints of a pericentric inversion of the X chromosome (46,X,inv[X][p21q27]) in a female patient with mild mental retardation revealed localization of the Xp breakpoint in the IL1RAPL gene at Xp21.3 and the Xq breakpoint near the SOX3 gene (SRY [sex determining region Y]-box 3) (GenBank accession number NM_005634) at Xq26.3. Because carrier females with microdeletion in the IL1RAPL gene do not present any abnormal phenotype, we focused on the Xq breakpoint. However, we were unable to confirm the involvement of SOX3 in the mental retardation in this female patient. To validate SOX3 as an X-linked mental retardation (XLMR) gene, we performed mutation analyses in families with XLMR whose causative gene mapped to Xq26-q27. We show here that the SOX3 gene is involved in a large family in which affected individuals have mental retardation and growth hormone deficiency. The mutation results in an in-frame duplication of 33 bp encoding for 11 alanines in a polyalanine tract of the SOX3 gene. The expression pattern during neural and pituitary development suggests that dysfunction of the SOX3 protein caused by the polyalanine expansion might disturb transcription pathways and the regulation of genes involved in cellular processes and functions required for cognitive and pituitary development.
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PMID:Transcription factor SOX3 is involved in X-linked mental retardation with growth hormone deficiency. 1242 12

Mental retardation (MR) is a symptom in a large group of clinical conditions and affects around 3% of the population. MR is divided into syndromic, if it is characterized by distinctive clinical features and nonspecific when mental retardation is the only defining manifestation. Although genetic causes of X-linked mental retardation (XLMR) are heterogenous and complex, recent findings have led to the identification of an increasing number of genes involved in these conditions. Eight genes involved in nonspecific X-linked mental retardation have been identified so far, including FMR2, GDI1, OPHN1, PAK3, ARHGEF6, IL1RAPL, TM4SF2, and FACL4. Four other MECP2, RSK2, ARX, ATR-X are involved in syndromic and nonspecific forms of MR. Recent research has shown that these genes encode for proteins involved in signaling pathways which regulate cytoskeleton organization, synaptic vesicle transport and establishment of connections between neuronal cells. These findings provide insight into the molecular mechanisms of crucial processes for the development of intellectual and cognitive functions.
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PMID:[Monogenic causes of nonspecific X-linked mental retardation molecular aspects]. 1281 Sep 81

We report on a 2 years and 9 months old Japanese boy with adrenal hypoplasia and mental retardation (MR) (developmental quotient approximately 60) which occurred in the absence of severe adrenal crisis and resultant brain damage. Cytogenetic and molecular studies were performed in this boy and his parents with normal phenotype, showing that the boy had a maternally derived approximately 2 Mb interstitial Xp deletion involving DAX1 (DSS-AHC critical region on the X chromosome, gene 1) for adrenal hypoplasia congenita and disrupting IL1RAPL (interleukin-1 receptor accessory protein-like) for non-specific MR. The results explain the development of MR in this boy in terms of contiguous gene syndrome, and suggest the importance of IL1RAPL analysis in patients with adrenal hypoplasia and MR.
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PMID:Mental retardation in a boy with congenital adrenal hypoplasia: a clue to contiguous gene syndrome involving DAX1 and IL1RAPL. 1294 Apr 59

In a 6 year old boy referred for mental retardation, fragile X syndrome was ruled out by cytogenetic and molecular analyses. Cytogenetic investigations revealed an inverted X chromosome (p21.3q27.1). A similar chromosomal rearrangement was detected in his mildly mentally retarded mother. Fluorescence in situ hybridization (FISH), using a panel of ordered YAC clones, allowed the identification of YACs spanning both the Xp21.3 and Xq27.1 breakpoints, where many non-specific mental retardation loci have been reported so far. Further investigations by FISH showed that the IL1RAPL1 gene at Xp21.3 was disrupted by the X chromosome inversion and therefore its inactivation may be related to the mental retardation observed in our patients.
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PMID:Dissection of an inverted X(p21.3q27.1) chromosome associated with mental retardation. 1461 Mar 52


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