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

Mice homozygous for the recessive mutation swaying (sw) are characterized by ataxia and hypertonia, attributed to the malformation of anterior regions of the cerebellum. We show that sw is a deletion of a single base pair from the proto-oncogene Wnt-1. The deletion is predicted to cause premature termination of translation, eliminating the carboxy-terminal half of the Wnt-1 protein. Histological examination shows that sw is phenotypically identical to a previously described wnt-1 mutation introduced into mice by gene targeting. Although both mutations in Wnt-1 disrupt primarily the development of the anterior cerebellum, they also exhibit a variability in expressivity such that rostrally adjacent structures in the midbrain and caudally adjacent structures in the posterior cerebellum can also be affected.
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PMID:Swaying is a mutant allele of the proto-oncogene Wnt-1. 183 70

The int-1 proto-oncogene was first identified as a gene activated in virally induced mouse mammary tumours. Expression studies, however, suggest that the normal function of this gene may be in spermatogenesis and in the development of the central nervous system. Genes sharing sequence similarity with int-1 have been found throughout the animal kingdom. For example, int-1 has 54% amino-acid identity to the Drosophila segment polarity gene wingless (wg). Both the int-1 and wg gene products seem to be secreted proteins, presumably involved in cell-cell signalling. We have now explored the function of int-1 in the mouse by disrupting one of the two int-1 alleles in mouse embryo-derived stem cells using positive-negative selection. This cell line was used to generate a chimaeric mouse that transmitted the mutant allele to its progeny. Mice heterozygous for the int-1 null mutation are normal and fertile, whereas mice homozygous for the mutation may exhibit a range of phenotypes from death before birth to survival with severe ataxia. The latter pathology in mice and humans is often associated with defects in the cerebellum. Examination of int-1-/int-1- mice at several stages of embryogenesis revealed severe abnormalities in the development of the mesencephalon and metencephalon indicating a prominent role for the int-1 protein is in the induction of the mesencephalon and cerebellum.
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PMID:Targeted disruption of the murine int-1 proto-oncogene resulting in severe abnormalities in midbrain and cerebellar development. 220 7

Treatment of rats with the central thiamine antagonist, pyrithiamine, results in severe neurological symptoms such as ataxia and convulsions. Induction of proto-oncogene c-fos expression, often related to seizure activity, has been detected in the brains of thiamine-deficient rats by means of Northern blot analysis and in situ hybridization. Region-selective increases of lactate observed following thiamine deficiency development are largely coincident with histologically vulnerable regions. When thiamine-deficient rats were treated with the calcium channel blocker, nicardipine, lesions associated with thiamine deficiency did not appear and there was no induction of c-fos mRNA expression. This suggests a neurocytoprotective role of nicardipine to neuronal cell damage in thiamine-deficient encephalopathy.
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PMID:Proto-oncogene c-fos induction in thiamine-deficient encephalopathy. Protective effects of nicardipine on pyrithiamine-induced lesions. 822 66

Due to the multisensory input into the balance system, the loss of one input, such as an ear, can generally be compensated for. However, when a mismatch or incomplete loss of inputs occurs, the ability to compensate for the stimulus misrepresentation may be compromised. The inner ear and cerebellum are important input and processing centers for balance but no genetic models have been generated to assess balance or compensation in the abnormal development of both these organs/brain areas. Important to their formation is regulation of proliferation mediated by the proto-oncogene N-Myc. Conditional knockouts (CKOs) of N-Myc using Tg(Pax2-Cre) have a misshapen and smaller ear with a fused utricle, saccule, and cochlea and absent horizontal canal, aberrant cochlear and vestibular innervations, and a size reduction in the cerebellum. CKOs are viable with obvious behavioral deficits, including circling behavior and unstable gait. To test the degree of ataxia and possible compensation of vestibular defects in these mutant mice, we use the Noldus Catwalk System to assess the gait of Tg(Pax2-Cre) N-Myc CKOs over five months. N-Myc CKOs perform worse than control littermates, in particular, in step regularity. We show that disrupting one member of the Myc family during embryonic development coincides with a differential loss of function in the cochlea compared to the vestibular apparatus. In addition, we show that the distortion in the ear morphology combined with a reduction of the cerebellum, rather than a complete loss of the vestibular-cerebellar pathway, leads to partial behavioral compensation that remains unchanged over time.
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PMID:Mutational ataxia resulting from abnormal vestibular acquisition and processing is partially compensated for. 2230 45

Erdheim-Chester disease (ECD) is a rare disorder characterized by accumulation of non-Langerhans cell histiocytes in multiple organs. The clinical manifestations are protean and vary from asymptomatic focal disease to potentially fatal multisystem disorder. The commonest presentation is symmetric osterosclerotic lesions of lower extremity long bones; other organs, including cardiovascular, nervous, and endocrine system may be affected. Central nervous system involvement can occur in up to 50% cases and is associated with poor prognosis. The disease pathogenesis involves organ involvement secondary to histiocytic infiltration and systemic inflammation driven by Th1 cytokine activation. The recent discovery of activating mutations in proto-oncogene B-rapidly accelerated fibrosarcoma (BRAF) V600E and other genes involved in mitogen-activated protein kinase (MAPK) pathways has led to redefinition of ECD as a myeloid neoplastic disorder. The diagnosis requires histochemical and molecular analysis of histiocytes in tissue biopsies in patients with compatible clinical and imaging features. The treatment options include interferon-alpha, anakinra, and immunosuppressive therapies. Better understanding of disease pathogenesis has led to development of novel targeted and effective therapies including BRAF and MEK inhibitors. The rarity of the disease and variable clinical features and course often results in diagnostic errors and delays. Rare primary neurological presentation can occur mimicking CNS inflammatory, neoplastic, or demyelinating disorders. We report an unusual case of ECD presenting with progressive encephalopathy and ataxia along with multifocal brainstem and cerebellar lesions. A comprehensive review of clinical and neuroimaging features and immunohistochemical and molecular characteristic of ECD are presented along with review of neuroimaging findings in two previously reported cases.
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PMID:Clinical and Neuroimaging Manifestations of Erdheim-Chester Disease: A Review. 3292 Sep 40