Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0004134 (ataxia)
 15,886 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Non-specific X-linked mental retardation is a heterogeneous group of disorders with an incidence of approximately 1 in 500 males. A recently identified gene in Xq12, encoding a Rho-GTPase-activating protein, was found to be mutated in individuals with mental retardation. We describe here two sisters with a 46,XY karyotype and a microdeletion of the oligophrenin-1 gene and 1.1 Mb of flanking DNA. We have characterised the molecular interval defining this microdeletion syndrome with the fibre-FISH technique. A visual physical map of 1.2 Mb was constructed which spans the oligophrenin-1 gene and the androgen receptor gene. The analysis of the patients revealed a deletion which extended from the 5' end of the AR gene to a region approximately 80 kb proximal to the EPLG2 gene. The clinical manifestations of the two sisters include psychomotor retardation, seizures, ataxia, hypotonia and complete androgen insensitivity. Cranial MRI scans show enlargement of the cerebral ventricles and cerebellar hypoplasia. Our findings give further support for the involvement of the oligophrenin-1 gene in specific morphological abnormalities of the brain which is of importance in the investigation of male patients presenting with mental retardation. In combination with our results from physical mapping we suggest that a region around the oligophrenin-1 locus is relatively bereft of vital genes.
 ...
PMID:Deletion including the oligophrenin-1 gene associated with enlarged cerebral ventricles, cerebellar hypoplasia, seizures and ataxia. 1043 59

Oligophrenin-1 (OPHN-1) gene disruption is known as responsible for so called "non-specific" X-linked mental retardation (MR) Billuart et al. [1998: Nature 392:923-926]. In order to search for a possible specific clinical and radiological profile for mutation in the OPHN-1 gene, clinical and 3D brain MRI studies were performed in the two families with a known mutation in OPHN-1 reported so far: a 19-year-old female with an X;12 balanced translocation encompassing OPHN-1, and four affected males of family MRX60 sharing a frameshift mutation in OPHN-1. Clinical data shared by affected individuals were neonatal hypotonia with motor delay but no obvious ataxia, marked strabismus, early onset complex partial seizures, and moderate to severe MR. Brain MRIs performed in three individuals exhibited a specific vermian dysgenesis including an incomplete sulcation of anterior and posterior vermis with the most prominent defect in lobules VI and VII. In addition, a non-specific cerebral cortico-subcortical atrophy was also observed. These clinical and radiological features suggest a distinct clinico-radiological syndrome. These preliminary data need to be confirmed in other families and will be helpful for further targeted mutation screening of the OPHN-1 gene in male patients with similar clinico-radiological features. In addition, OPHN-1 inactivation should be considered as a relevant model of developmental vermis disorganization, leading to a better understanding of the possible role of the cerebellum in MR.
 ...
PMID:Specific clinical and brain MRI features in mentally retarded patients with mutations in the Oligophrenin-1 gene. 1473 83

We report on a newly discovered serum and cerebrospinal fluid (CSF) reactivity to Purkinje cells (PCs) associated with subacute inflammatory cerebellar ataxia. The patient, a previously healthy 33-year-old lady, presented with severe limb and gait ataxia, dysarthria, and diplopia two weeks after she had recovered from a common cold. Immunohistochemical studies on mouse, rat, and monkey brain sections revealed binding of a high-titer (up to 1:10,000) IgG antibody to the cerebellar molecular layer, Purkinje cell (PC) layer, and white matter. The antibody is highly specific for PCs and binds to the cytoplasm as well as to the inner side of the membrane of PC somata, dendrites and axons. It is produced by B cell clones within the CNS, belongs to the IgG1 subclass, and activates complement in vitro. Western blotting of primate cerebellum extract revealed binding of CSF and serum IgG to an 80-97 kDa protein. Extensive control studies were performed to rule out a broad panel of previously described paraneoplastic and non-paraneoplastic antibodies known to be associated with cerebellar ataxia. Screening of >9000 human full length proteins by means of a protein array and additional confirmatory experiments revealed Rho GTPase activating protein 26 (ARHGAP26, GRAF, oligophrenin-1-like protein) as the target antigen. Preadsorption of the patient's serum with human ARHGAP26 but not preadsorption with other proteins resulted in complete loss of PC staining. Our findings suggest a role of autoimmunity against ARHGAP26 in the pathogenesis of subacute inflammatory cerebellar ataxia, and extend the panel of diagnostic markers for this devastating disease.
 ...
PMID:A new Purkinje cell antibody (anti-Ca) associated with subacute cerebellar ataxia: immunological characterization. 2022 58