Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0085584 (encephalopathy)
 18,178 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Gait disorder is a common complaint in general practice, in particular in the elderly, and more than one cause frequently interact to produce various abnormalities of gait, including neurological, orthopedic, rhumatologic or ophthalmologic conditions, among others. The most frequent etiologies of gait impairment include sensory deficits, cervical myelopathy, vascular encephalopathy, parkinsonism and normal pressure hydrocephalus. In a particular individual, several of them may contribute to alter gait and, as a general rule, the treatment of these well-established conditions is generally considered difficult. Besides them, a number of rare and underrecognized neurological conditions may also produce a gait disorder as their initial, main or exclusive feature, including dopa-responsive dystonia, stiff-person syndrome, orthostatic tremor, primary progressive freezing gait and cursive epilepsy. In this review article, the clinical, therapeutic and other characteristics of these conditions are revisited and a typical illustrative case is reported for each. Since most of these conditions are responsive to specific treatments, we believe that a better knowledge of these unusual forms of gait disorder may allow general practitioners to identify them more accurately, to assess them and to improve therapeutic strategies.
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PMID:[Unusual causes of gait disorders]. 1509 29

Tyrosine hydroxylase (TH) deficiency is a rare autosomal recessive disorder mapped to chromosome 11p15.5. Its clinical expression varies with presentations as dopa-responsive dystonia (recessive Segawa's disease), dopa-responsive infantile parkinsonism, dopa-responsive spastic paraplegia, progressive infantile encephalopathy or dopa-non-responsive dystonia. We describe a 7-year-old boy with progressive infantile encephalopathy and non-responsiveness to dopamine. The patient demonstrated generalized hypotonia, pyramidal tract dysfunction and temperature instability after the second month of life. Dystonia, tremor and oculogyric crises complicated the clinical picture during the following months. Neurotransmitter analysis in CSF disclosed almost undetectable levels of HVA and MHPG, whereas serum prolactin was profoundly increased. Subsequent molecular analysis revealed homozygosity for a missense mutation (c.707T>C) in the TH gene. l-Dopa therapy in both high and low doses resulted in massive hyperkinesias, while substitution with selegiline exerted only a mild beneficial effect. Today, at the age of 7 years, the patient demonstrates severe developmental retardation with marked trunkal hypotonia, hypokinesia and occasionally dystonic and/or hyperkinetic crises. He is the third Greek patient with TH deficiency to be reported. Since all three patients carry the same pathogenetic mutation, a founder effect is suspected.
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PMID:Tyrosine hydroxylase deficiency with severe clinical course. 1928 9

This study included 12 Chinese patients with a wide spectrum of phenotypes of tyrosine hydroxylase deficiency. Seven females and 5 males, aged 2.2 to 41 years, had phenotypes ranging from severe type with onset at infancy to mild type with onset after 3 years of age. Patients with the severe type had encephalopathy with poor treatment response or infantile parkinsonism with motor delay. Patients with the less common mild type had dopa-responsive dystonia or a newly recognized predominant symptom of myopathy. Female siblings had more severe phenotypes. The phenotype and treatment outcomes were strongly related to a homovanillic acid level and homovanillic acid/5-hydroxyindolacetic acid ratio of less than 1 in the cerebrospinal fluid. Hyperprolactinemia was found in 50% of the severe cases. Levodopa was the mainstay of treatment, and early addition of selegiline resulted in a remarkable response in some patients. Treatment response for mild-type patients is universally good even with a treatment delay of 10 years after onset of neurological symptoms.
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PMID:Expanding phenotype and clinical analysis of tyrosine hydroxylase deficiency. 2082 27

In a recent GCH1 mutation screen, an 18-bp deletion was identified within the proximal promoter in two patients with early-onset Parkinson's disease. The mutation removes cAMP response element critical for adequate GTP cyclohydrolase I activity in selected cell types, including dopaminergic neurons, but its biological significance was unclear as it was also detected in one control individual. We present an 11-year-old boy with infantile-onset severe dystonic encephalopathy without hyperphenylalaninemia whom we found compound heterozygous for the same promoter GCH1 deletion and another common missense mutation associated with classical dopa-responsive dystonia. Extensive diagnostic work up excluded other causes of dystonia, and comprehensive mutation scan did not reveal any additional GCH1 sequence variations, supporting the association between the promoter deletion and disease phenotype.
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PMID:Severe dystonic encephalopathy without hyperphenylalaninemia associated with an 18-bp deletion within the proximal GCH1 promoter. 2084 87

Neurometabolic diseases diagnosed by cerebrospinal fluid (CSF) examination are GLUT1 deficiency, serine-deficiency syndromes, glycine encephalopathy, cerebral folate deficiency, neonatal vitamin-responsive epileptic encephalopathies, disorders of monoamine metabolism, and y-amino butyric acid (GABA) metabolism. We retrospectively analyzed and compared the demographic, clinical, laboratory, and neuroimaging features of 62 patients in whom CSF examination was performed. Of the 62 patients, 16 (25.8%) had a final diagnosis, including succinic semialdehyde dehydrogenase (SSADH) deficiency (n=4), aromatic amino acid decarboxylase (AADC) deficiency (n=4), L-dopa-responsive dystonia (n=3), glycine encephalopathy (n=2), pyridoxal-phosphate-dependent seizures (n=l), cerebral folate deficiency (n=1), and serine biosynthesi defect (n=1). Parental consanguinity was present in all patients except one Positive yield of a diagnostic lumbar puncture (LP) for the diagnosis of inherited neurotransmitter metabolism disorder was 25.8% overall. Oculogyric crisis (50%), diurnal variation (81.8%) and consanguinity (93.8%) were the only statistically significant variables between patients with and without a specific diagnosis. It is challenging to diagnose neurotransmitter defects, since there is no ideal set of clinical symptoms. In our cohort, consanguinity, diurnal variation and abnormal ocular movements were the most significant findings associated with a diagnosis of a specific neurometabolic disorder based on CSF examination. Early diagnosis is of great importance not only for specific treatment, but also for genetic counseling and prenatal diagnosis.
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PMID:When do we need to perform a diagnostic lumbar puncture for neurometabolic diseases? Positive yield and retrospective analysis from a tertiary center. 2239 43

Tyrosine hydroxylase (TH) is a tetrahydrobiopterin (BH4) dependent enzyme that catalyses the conversion of L-tyrosine to L-dopa, the rate-limiting step in the biosynthesis of dopamine. Autosomal recessive mutations in the TH gene cause impaired TH activity and are associated with phenotypes ranging from autosomal recessive dopa-responsive dystonia (DRD) to progressive infantile encephalopathy. Herein, we present a patient with TH-deficiency due to two compound heterozygous missense mutations in the TH/gene, one of which is novel (p.R441P). A clinical update on TH-deficiency and clues on how to achieve a timely diagnosis of this highly treatable disorder is provided.
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PMID:A novel compound heterozygous tyrosine hydroxylase mutation (p.R441P) with complex phenotype. 2393 62

Neurodegenerative diseases that afflict nervous system are characterized by progressive nervous system dysfunction and associated with the one-set of many diseases like Segawa's syndrome (recessive form), autosomal recessive L-dopa-responsive dystonia, L-dopa non-responsive dystonia or progressive early-onset encephalopathy and recessive L-dopa-responsive parkinsonism. It has been reported that a number of mutations in coding regions, splice sites and promoter regions of tyrosine hydroxylase (TH) are associated with many such diseases. TH is responsible for catalyzing the conversion of L-tyrosine to L-3,4-dihydroxyphenylalanine. This reaction is considered as rate-limiting step in the biosynthesis of catecholamines, dopamine, norepinephrine and epinephrine, which has made TH an important target for drug development. In our previous study using comparative molecular docking approach, it was concluded that [4-(Propan-2-yl) Phenyl]Carbamic acid (PPCA) may serve as a potential inhibitor. By further extending, our focus is to determine the binding affinities of PPCA and mutated TH. 3D structures of mutated TH were predicted and subjected to molecular docking studies. PPCA was found to bind in the deep narrow groove lined with polar and aromatic amino acids in 14 out of 17 mutants under study (R202H, L205P, H215Y, G216S, T245P, F278P, T283M, R297W, R306H, C328F, A345V, L356M, T368M, Q381K, P461L, T463M and D467G). Our results corroborate efficient binding of PPCA with normal and mutated TH, indicating that PPCA might be a strong therapeutic candidate for the management of Parkinson's disease and other related disorders. It may be a valuable target for evaluation in preclinical models.
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PMID:Computational study of human tyrosine hydroxylase mutants to uphold [4-(Propan-2-yl) Phenyl]Carbamic acid as a potential inhibitor. 2523 Feb 30