Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:6.3.2.19 (ubiquitin-protein ligase)
 799 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Of the chronic mental disabilities of childhood, autism is causally least well understood. The former view that autism was rooted in exposure to humorless and perfectionistic parenting has given way to the notion that genetic influences are dominant underlying factors. Still, identification of specific heritable factors has been slow with causes identified in only a few cases in unselected series. A broad search for genetic and environmental influences that cause or predispose to autism is the major thrust of the South Carolina Autism Project. Among the first 100 cases enrolled in the project, abnormalities of chromosome 15 have emerged as the single most common cause. The four abnormalities identified include deletions and duplications of proximal 15q. Other chromosome aberrations seen in single cases include a balanced 13;16 translocation, a pericentric inversion 12, a deletion of 20p, and a ring 7. Candidate genes involved in the 15q region affected by duplication and deletion include the ubiquitin-protein ligase (UBE3A) gene responsible for Angelman syndrome and genes for three GABA(A) receptor subunits. In all cases, the deletions or duplications occurred on the chromosome inherited from the mother.
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PMID:Autism and maternally derived aberrations of chromosome 15q. 954 97

Angelman syndrome is a severe neurodevelopmental disorder with cognitive impairment and neurological deficits. It results from a maternal deletion of human chromosome 15q11-13 containing two candidate genes E6-P ubiquitin-protein ligase (UBE3A) and GABA(A) receptor beta3 subunit (GABRB3), the latter of which has been also linked to autism. To clarify the potential role of GABA(A) beta3 subunit-containing inhibitory receptors in these disorders, we applied ligand autoradiography on brain sections from mice with inactivated GABRB3 or maternal UBE3A genes. Binding of GABA(A) receptor channel ([(35)S]t-butylbicyclophosphorothionate) and benzodiazepine ([(3)H]Ro 15-4513) site ligands was reduced in selected brain regions of the beta3-deficient mice as compared to controls, while the UBE3A-deficient mice failed to show reduced GABA(A) receptors. The results, suggesting two different pathophysiological mechanisms, are in agreement with positron emission tomography results from Angelman syndrome patients of the corresponding genetic backgrounds.
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PMID:Mouse models of Angelman syndrome, a neurodevelopmental disorder, display different brain regional GABA(A) receptor alterations. 1267 42