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

Using an interspecific backcross, we have mapped the gene involved in the mouse Small eye mutation (SeyMH) relative to six cloned markers on chromosome 2 (Hox-5.1, Cas-1, Fshb, Bmp-2a, and ld) and the agouti locus. The results suggest that the Sey gene maps between Fshb and Cas-1. Human mapping studies have shown that the aniridia (AN2) gene, which is part of the Wilms tumor susceptibility, aniridia, genitourinary abnormalities, and mental retardation (WAGR) complex, is also between FSHB and CAT on human chromosome 11. The conserved linkage of the cloned markers and the similarity of the Sey/+ and AN2/+ phenotypes suggest that the gene involved in the Sey mutation is the mouse homolog of the human AN2 gene.
 ...
PMID:Location of the gene involving the small eye mutation on mouse chromosome 2 suggests homology with human aniridia 2 (AN2). 234 91

Down syndrome (DS), a major cause of mental retardation, is characterized by subtle abnormalities of cortical neuroanatomy, neurochemistry and function. Recent work has shown that chromosome band 21q22 is critical for many of the neurological phenotypes of DS. A gene, DSCAM (Down syndrome cell adhesion molecule), has now been isolated from chromosome band 21q22.2-22.3. Homology searches indicate that the putative DSCAM protein is a novel member of the immunoglobulin (Ig) superfamily that represents a new class of neural cell adhesion molecules. The sequence of cDNAs indicates alternative splicing and predicts two protein isoforms, both containing 10 Ig-C2 domains, with nine at the N-terminus and the tenth located between domains 4 and 5 of the following array of six fibronectin III domains, with or without the following transmembrane and intracellular domains. Northern analyses reveals the transcripts of 9.7, 8.5 and 7.6 kb primarily in brain. These transcripts are differentially expressed in substructures of the adult brain. Tissue in situ hybridization analyses of a mouse homolog of the DSCAM gene revealed broad expression within the nervous system at the time of neuronal differentiation in the neural tube, cortex, hippocampus, medulla, spinal cord and most neural crest-derived tissues. Given its location on chromosome 21, its specific expression in the central nervous system and neural crest, and the homologies to molecules involved in neural migration, differentiation, and synaptic function, we propose that DSCAM is involved in neural differentiation and contributes to the central and peripheral nervous system defects in DS.
 ...
PMID:DSCAM: a novel member of the immunoglobulin superfamily maps in a Down syndrome region and is involved in the development of the nervous system. 942 58

We previously postulated that the single-minded 2 (SIM2) gene identified on the human chromosome 21q22.2 is a good candidate gene for the pathogenesis of mental retardation in Down syndrome because its mouse homolog exhibits preferential expression in the mouse diencephalon during early embryogenesis. We analyzed the genomic sequence of the entire SIM2 gene which consists of 11 exons and spans over 50 kb. As a step toward understanding the molecular mechanisms of SIM2 gene expression, we have analyzed the human SIM2 gene expression in nine established human cell lines. Three transcripts of 3.6, 4.4, and 6.0 kb were detected in the glioblastoma cell line, T98G, neuroblastoma cell line, TGW, and transformed embryonic kidney cell line, 293. The RACE analysis using SIM2-expressing human cell line T98G provided evidence for the transcription start site at approximately 1.2 kb upstream of the translation initiation site. The transfection assay using various deletion constructs with reporter gene suggested the presence of a presumptive promoter region. Transient transfection assay in T98G cell line revealed a significant promoter activity located in the 60 bp sequence between nt -1385 and -1325 upstream region of the translation initiation site. This 60 bp sequence contains cis-elements for c-myb, E47 and E2F transcription factors. Moreover, the gel retardation assay using oligo-DNA of various cis-element sequences indicated the presence of protein factor(s) which bind to the cis-element for c-myb. These results suggested that binding of a protein transcription factor(s) such as c-myb or that alike regulates transcription of the SIM2 gene by binding to a small upstream region.
 ...
PMID:Molecular mechanisms of human single-minded 2 (SIM2) gene expression: identification of a promoter site in the SIM2 genomic sequence. 1140 25

The cerebral cortex is a tissue with a high degree of neuronal diversity. It consists of six cell layers with a unique set of neuronal subtypes. A crucial step in the process of cortical differentiation is the transition from a mitotically active neuroblast to a postmitotic young neuron. To identify genes involved in the control of this transition, we applied a novel method of cDNA subtraction based on mirror-orientation selection. One of the genes we have identified in our screening proved to be a mouse homolog of the human putative transcription factor LAF4. We identified alternatively spliced forms of mouse Laf4 that encode several forms of putative protein with potentially different transactivation functions. Two forms are expressed mainly during embryogenesis, whereas the other forms are expressed mainly in adults. We have found that Laf4 transcription becomes very quickly upregulated as soon as young cortical neurons leave the ventricular zone (VZ), the cortical-proliferative compartment. This coincides with the initial steps of cortical differentiation. Laf4 becomes downregulated in postnatal cortex, indicating its involvement in the transcriptional regulation of the early steps of cortical differentiation. We have also examined Laf4 expression in the brains of Sey and reeler mutants. Laf4 was downregulated in the lateroventral part of the cerebral cortex and completely lost in the piriform cortex of the Sey mutant embryos. We also compared its expression during central nervous system development with that of its closest homolog, Fmr2, a gene implicated in mental retardation in humans.
 ...
PMID:The mouse Laf4 gene: exon/intron organization, cDNA sequence, alternative splicing, and expression during central nervous system development. 1207 80

Wilms tumor, aniridia, genitourinary anomalies, and mental retardation (WAGR) syndrome is a contiguous gene deletion syndrome involving the Wilms tumor 1 gene (WT1), the paired box gene 6 (PAX6), and possibly other genes on chromosome 11p13. WT1 is required for normal formation of the genitourinary system and the high incidence of Wilms tumor and genitourinary anomalies found in patients with WAGR are attributed to haploinsufficiency of this gene. It has been hypothesized that WT1 also plays an important role in the development of the diaphragm. During mammalian embryonic development, WT1 is expressed in the pleural and abdominal mesothelium that forms part of the diaphragm. Furthermore, mice that are homozygous for a deletion in the mouse homolog of WT1 have diaphragmatic hernias. Case reports describing congenital diaphragmatic hernias in infants with Denys-Drash and Frasier syndromes, both of which can be caused by mutations in WT1, provide additional support for this hypothesis. We report an infant with aniridia, bilateral cryptorchidism, vesicoureteral reflux, and a right-sided Morgagni-type diaphragmatic hernia. G-banded chromosome analysis revealed a deletion of 11p12-p15.1. Breakpoint regions were refined by fluorescence in situ hybridization (FISH) and deletion of the WAGR critical region, including WT1, was confirmed. A review of the medical literature identified a second patient with a deletion of 11p13, a left-sided Bochdalek-type diaphragmatic hernia, and anomalies that suggest a diagnosis of WAGR including bilateral microphthalmia, a small penis, bilateral cryptorchidism, and a hypoplastic scrotum. These cases demonstrate that congenital diaphragmatic hernia can be associated with WAGR syndrome and suggest that deletions of WT1 may predispose individuals to develop congenital diaphragmatic hernia.
 ...
PMID:Congenital diaphragmatic hernia in WAGR syndrome. 1577 10