Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0007758 (cerebellar ataxia)
 3,609 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Nineteen patients (9 females, 10 males) with mitochondrial encephalomyopathies (ME) were studied. The diagnosis was established according to clinical and histopathological criteria. Leading clinical features were chronic progressive external ophthalmoplegia (CPEO) and muscle weakness in 95% of the patients. Pigmentary retinopathy was seen in 63%, and was always associated with CPEO. Hypacusis was present in 47% and cerebellar ataxia in 63% of patients. Clinical or electrophysiological signs of involvement of the central nervous system (CNS) were found in 21% of the patients. In muscle biopsy ragged red fibers were the predominant histopathological findings (100% of the patients), while COX-negative fibers were seen in 74%, deletions of the mitochondrial DNA in 42%, and defects of the respiratory chain in 32% of the patients. Increased blood lactate levels were found in 79% of the patients. Needle electromyography revealed myopathic features in 74%, features of denervation in 16%, and was normal in the remainder. Imaging studies showed cerebral atrophy in 58%, cerebellar atrophy in 16%, and hyperintense lesions of the white matter, pyramidal tract or extrapyramidal system in 16% of the cases. It is concluded that the clinical manifestations of ME can be very variable. Diagnosis of ME should be always considered in young patients presenting with CPEO and muscle weakness. In most cases, diagnosis can be made by a few selected investigations, while detection of genetic abnormalities may lead to the diagnosis in the remaining cases.
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PMID:Clinical, morphological, biochemical, and neuroradiological features of mitochondrial encephalomyopathies. Presentation of 19 patients. 930 3

We report a 70-year-old woman with bilateral optic atrophy, external ophthalmoplegia, bilateral blepharoptosis, and sensory ataxic neuropathy. She had a visual disturbance since childhood. She had dysarthria and gait disturbance at 28 years old. She had bilateral blepharoptosis, marked gait disturbance and dysphagia at 50. On neurological examination, external ophthalmoplegia, bilateral blepharoptosis, mild weakness and muscular atrophy of promixal muscles, hyporeflexia, positive Romberg sign, glove and stocking type sensory disturbance including hypesthesia, hypalgesia, and bathyhypesthesia were found. She did not show pigmented retinopathy, cognitive dysfunctions, hearing loss, cerebellar ataxia, Hoffman reflex nor Babinski sign. She did not show increased lactic acid nor pyruvic acid in the cerebrospinal fluid but mild increase of pyruvic acid (1.0 mg/dl) in her serum. The conduction velocity and amplitude of CMAP of tibial nerve was 37.4 m/sec and 2.9 mV, respectively. The SNAP of ulner and sural nerve were not evoked. Brain MRI showed no pathological findings. Muscle biopsy from the biceps muscle showed many ragged-red fibers (5.3%) and some fibers with decreased or absent COX activity. Sural nerve biopsy showed a marked loss of large myelinated fibers with thin myelinated fibers, and onion-bulb formation. The clinical findings of our patient is similar to that of SANDO (the triad of sensory ataxic neuropathy, dysarthria, and ophthalmoparesis), however, large mtDNA deletion reported by Fadic in patients with SANDO was not found in our patient. It might be possible that her mtDNA deletion is small or point mutation is existed.
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PMID:[A case of mitochondrial myopathy with external ophthalmoplegia and ataxic neuropathy]. 1472 65

Both nuclear and mitochondrial DNA defects can cause isolated cytochrome c oxidase (COX; complex IV) deficiency, leading to the development of the mitochondrial disease. We report a 52-year-old female patient who presented with a late-onset, progressive cerebellar ataxia, tremor and axonal neuropathy. No family history of neurological disorder was reported. Although her muscle biopsy demonstrated a significant COX deficiency, there was no clinical and electromyographical evidence of myopathy. Electrophysiological studies identified low frequency sinusoidal postural tremor at 3 Hz, corroborating the clinical finding of cerebellar dysfunction. Complete sequencing of the mitochondrial DNA genome in muscle identified a novel MT-CO2 variant, m.8163A>G predicting p.(Tyr193Cys). We present several lines of evidence, in proving the pathogenicity of this heteroplasmic mitochondrial DNA variant, as the cause of her clinical presentation. Our findings serve as an important reminder that full mitochondrial DNA analysis should be included in the diagnostic pipeline for investigating individuals with spinocerebellar ataxia.
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PMID:A Novel Pathogenic Variant in MT-CO2 Causes an Isolated Mitochondrial Complex IV Deficiency and Late-Onset Cerebellar Ataxia. 3116 10