Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0013362 (dysarthria)
 3,768 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The arguments over the nomenclature of the syndrome are reviewed. Ethical considerations favour replacing the present eponyms with the title of panthothenate kinase-associated neurodegeneration (PKAN), now that more is known about the cause of the condition. The symptoms and signs of the syndrome are described, and these can present from infancy to adult life. Dystonia, involuntary movements and spasticity are prominent causes of disability. If the onset is delayed the presentation can be unusual. Tests that can help in diagnosis are reviewed, especially the "eye of the tiger" revealed by magnetic resonance imaging scanning. Death usually occurs about 10 years after the onset, but the course may be more prolonged. The findings on autopsy are also considered, with the typical findings of iron pigment deposits and axonal spheroids. Then the causes are discussed. Once the responsible gene PANK2 had been discovered on chromosome 20 it was found that this encoded for pantothenate kinase which is essential for the synthesis of coenzyme A from pantothenate; and this is integral to fatty acid synthesis and energy metabolism. Also this can lead to a concentration of cysteine in the basal ganglia, and then to an accumulation of iron in these areas. The cysteine-iron complex will result in tissue damage by promoting oxidative stress, as in some other neurodegenerative diseases. The syndrome of PKAN can therefore be identified as a disorder of pantothanate, vitamin B5, metabolism. Infantile neuroaxonal dystrophy is briefly described as there have been suggestions that it is a variety of PKAN, but the evidence is in favour of the two diseases being separate entities. There may as yet be no specific treatment for this syndrome, but much can be done to help these children. Drugs may be needed to control epilepsy, and when dystonia is severe it may be possible to alleviate this by medical or surgical means. Also there will be other problems needing expert management, such as the provision of alternative means of communication if dysarthria is marked. The hope for the future is that now the cause has been found it will be possible to use methods such as antioxidative therapy and gene induction procedures.
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PMID:Pantothenate kinase-associated neurodegeneration (Hallervorden-Spatz syndrome). 1237 76

Pantothenate kinase-associated neurodegeneration (PKAN) (MIM 234200; Hallervorden-Spatz syndrome) is a degenerative, autosomal recessive disorder in childhood, currently without specific treatment. In contrast to variable clinical features, T2-weighted magnetic resonance images show a characteristic 'eye-of-the-tiger sign' in the globus pallidus due to excess iron deposition. Recently a defect in pantothenate kinase, the key regulatory enzyme in the synthesis of coenzyme A from pantothenate, has been identified as the cause of the disease. We report a 12-year-old boy with progressive rigidity, dystonia, impaired voluntary movement, dysarthria, and mental deterioration. Over 10 years the boy had been misdiagnosed with clumsiness, emotional and behavioural deficits, and attention deficit disorder, before neuroimaging was performed showing the characteristic 'eye-of-the-tiger sign'. Molecular analyses confirmed two mutations in the PANK2 gene [coding sequence of a gene that has homology to murine pantothenate kinase-1]. We conclude that in progressive childhood dystonia, PKAN should be considered and magnetic resonance imaging performed early. The newly described defect of the pantothenate kinase enzyme enables a novel therapeutic approach to be considered, based on the mutation analyses of the PANK2 gene, as well as the prenatal diagnosis of this disorder.
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PMID:Progressive dystonia in a 12-year-old boy. 1269 33

Hallervorden-Spatz syndrome (HSS) is a neurodegenerative disorder characterized by progressive dementia, dystonia, ataxia, and rigidity. An atypical form of adult-onset HSS was observed in a 36-year-old man presenting with progressive dysarthria. Markedly dysarthric speech and a weak atrophic tongue associated with a neurogenic pattern of motor unit recruitment in bulbar-supplied muscles on electromyography led to an initial impression of bulbar amyotrophic lateral sclerosis (ALS). Lack of expected progression of symptoms, however, prompted reinvestigation. Repeat brain magnetic resonance imaging demonstrated an "eye-of-the-tiger" pattern in the basal ganglia, characteristic of HSS, thus requiring genetic studies. DNA analyses of the pantothenate kinase gene (PANK2) was conducted and revealed two novel, disease-causing exon 3 missense mutations (Cys231Ser and Tyr251Cys). This case broadens the genotypic and phenotypic spectrum of HSS to include a late-onset syndrome resembling bulbar-onset ALS.
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PMID:Adult Hallervorden-Spatz syndrome simulating amyotrophic lateral sclerosis. 1281 83

We investigated the presence of mutations in the pantothenate kinase (PANK2) gene in a 27-year-old male Chinese patient with atypical pantothenate kinase-associated neurodegeneration (PKAN), formerly Hallervorden-Spatz syndrome. Automated DNA sequence analyses revealed compound heterozygous mutations in the exon 3 and 5. This patient had a 10-year history of PKAN characterized by a slight tremor of the right hand when writing at onset and a slow progressive rigidity of the neck and the right arm and resting tremor in upper extremities. Dysarthria, dysphagia, and dystonic-athetoid movements of the face and right fingers were marked. Magnetic resonance showed the typical "eye-of-the-tiger" sign.
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PMID:Novel compound heterozygous mutations in the PANK2 gene in a Chinese patient with atypical pantothenate kinase-associated neurodegeneration. 1574 60

We describe an atypical case of pantothenate kinase-associated neurodegeneration (PKAN) in which slowly progressive arm tremor was the predominant symptom beginning at the age of 25, with late-onset dystonia and dysarthria developing at the age of 50. Compound heterozygous mutations resulting in missense amino acid substitutions G521R and I529V were identified in the pantothenate kinase (PANK2) gene. We demonstrate that while the G521R mutation results in an unstable and inactive protein, the previously unreported I529V substitution has no apparent effect on the stability or catalytic activity of PanK2. The phenotype that results from this combination of mutations suggests that atypical presentations of PKAN may arise from partial deficits in PanK2 catalytic activity.
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PMID:Partial deficit of pantothenate kinase 2 catalytic activity in a case of tremor-predominant neurodegeneration with brain iron accumulation. 1645 Mar 44

A 47-year-old man with a 15-year history of bipolar disorder treated with anti-depressants, lithium carbonate or neuroleptics was admitted because of marked difficulty in gait and speech. At the age 45, he was unable to walk without bilateral assists and became a wheel-chair state. There was no family history and his mother, father and younger sister were neurologically free. General physical examinations revealed no abnormalities. Neurologically, he was moderately demented (mini mental state examination: 18/30) and showed bilateral horizontal gaze nystagmus, parkinsonism, cerebellar ataxia, dysarthria and moderate spastic paraparesis. No involuntary movements were noted. Wet blood smear showed acanthocytes, while blood chemistries revealed no abnormalities including levels of serum creatine kinase, hepatic enzymes and blood beta-lipoprotein. Kell antigen expressions of the red blood cells were within normal limit. Western blot analysis with anti-chorein antibody detected normal chorein expression levels of the red blood cells. Cranial MRI showed severe symmetric atrophy of the frontotemporal lobes, caudate nuclei, putamen, and brainstem. Also, MRI-gradient echo showed symmetric iron accumulation in the medial portion of the globus pallidus without surrounding high intensity areas, so called "eye-of-the-tiger sign". Genetic analyses revealed no mutations in the PANK2 and PLA2G6 genes. Therefore, he was diagnosed as idiopathic neurodegeneration with brain iron accumulation (NBIA). These findings suggest that NBIA is heterogeneous and other additional genes remain to be found.
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PMID:[Adult-onset case of idiopathic neurodegeneration with brain iron accumulation without mutations in the PANK2 and PLA2G6 genes]. 1982 96

Hallervorden-Spatz disease is a rare neurological disorder characterized by pyramidal and extrapyramidal manifestations, dysarthria and dementia. Its onset is usually in childhood and most patients have a fatal outcome in few years. A high percentage of cases are hereditary with a recessive autosomal pattern. In the majority of the patients reported, a mutation of the gene that encodes the pantothenate kinase (PANK2) located in the 20p13-p12.3 chromosome that causes iron storage in the basal ganglia of the brain has been found. Its diagnosis is based on clinical symptoms as well as specific MRI imaging findings. The most common psychiatric features are cognitive impairment as well as depressive symptoms. There are few documented cases with psychotic disorders. We present the case of a patient with late onset Hallervorden-Spatz disease and psychotic symptoms that preceded the development of neurological manifestations. The pathophysiology and the treatment of psychotic symptomatology are presented and discussed. Key words: Psicosis, Hallervorden-Spatz, late onset, Basal ganglia.
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PMID:Adult onset Hallervorden-Spatz disease with psychotic symptoms. 2176 49

Pantothenate kinase-associated neurodegeneration (PKAN) is a hereditary progressive disorder and the most frequent form of neurodegeneration with brain iron accumulation (NBIA). PKAN patients present with a progressive movement disorder, dysarthria, cognitive impairment and retinitis pigmentosa. In magnetic resonance imaging, PKAN patients exhibit the pathognonomic "eye of the tiger" sign in the globus pallidus which corresponds to iron accumulation and gliosis as shown in neuropathological examinations. The discovery of the disease causing mutations in PANK2 has linked the disorder to coenzyme A (CoA) metabolism. PANK2 is the only one out of four PANK genes encoding an isoform which localizes to mitochondria. At least two other NBIA genes (PLA2G6, C19orf12) encode proteins that share with PANK2 a mitochondrial localization and all are suggested to play a role in lipid homeostasis. With no causal therapy available for PKAN until now, only symptomatic treatment is possible. A multi-centre retrospective study with bilateral pallidal deep brain stimulation in patients with NBIA revealed a significant improvement of dystonia. Recently, studies in the PANK Drosophila model "fumble" revealed improvement by the compound pantethine which is hypothesized to feed an alternate CoA biosynthesis pathway. In addition, pilot studies with the iron chelator deferiprone that crosses the blood brain barrier showed a good safety profile and some indication of efficacy. An adequately powered randomized clinical trial will start in 2012. This review summarizes clinical presentation, neuropathology and pathogenesis of PKAN.
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PMID:Pantothenate kinase-associated neurodegeneration. 2251 41

Neurodegeneration with brain iron accumulation (NBIA) comprises a group of neurodegenerative disorders characterized by high brain content of iron and presence of axonal spheroids. Mutations in the PANK2 gene, which encodes pantothenate kinase 2, underlie an autosomal recessive inborn error of coenzyme A metabolism, called pantothenate kinase-associated neurodegeneration (PKAN). PKAN is characterized by dystonia, dysarthria, rigidity and pigmentary retinal degeneration. The pathogenesis of this disorder is poorly understood and, although PANK2 is a mitochondrial protein, perturbations in mitochondrial bioenergetics have not been reported. A knock-out (KO) mouse model of PKAN exhibits retinal degeneration and azoospermia, but lacks any neurological phenotype. The absence of a clinical phenotype has partially been explained by the different cellular localization of the human and murine PANK2 proteins. Here we demonstrate that the mouse Pank2 protein localizes to mitochondria, similar to its human orthologue. Moreover, we show that Pank2-defective neurons derived from KO mice have an altered mitochondrial membrane potential, a defect further corroborated by the observations of swollen mitochondria at the ultra-structural level and by the presence of defective respiration.
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PMID:Pantothenate kinase-associated neurodegeneration: altered mitochondria membrane potential and defective respiration in Pank2 knock-out mouse model. 2298 56

Pantothenate kinase-associated neurodegeneration, caused by mutations in the PANK2 gene, is an autosomal recessive disorder characterized by dystonia, dysarthria, rigidity, pigmentary retinal degeneration and brain iron accumulation. PANK2 encodes the mitochondrial enzyme pantothenate kinase type 2, responsible for the phosphorylation of pantothenate or vitamin B5 in the biosynthesis of co-enzyme A. A Pank2 knockout (Pank2(-/-)) mouse model did not recapitulate the human disease but showed azoospermia and mitochondrial dysfunctions. We challenged this mouse model with a low glucose and high lipid content diet (ketogenic diet) to stimulate lipid use by mitochondrial beta-oxidation. In the presence of a shortage of co-enzyme A, this diet could evoke a general impairment of bioenergetic metabolism. Only Pank2(-/-) mice fed with a ketogenic diet developed a pantothenate kinase-associated neurodegeneration-like syndrome characterized by severe motor dysfunction, neurodegeneration and severely altered mitochondria in the central and peripheral nervous systems. These mice also showed structural alteration of muscle morphology, which was comparable with that observed in a patient with pantothenate kinase-associated neurodegeneration. We here demonstrate that pantethine administration can prevent the onset of the neuromuscular phenotype in mice suggesting the possibility of experimental treatment in patients with pantothenate kinase-associated neurodegeneration.
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PMID:Pantethine treatment is effective in recovering the disease phenotype induced by ketogenic diet in a pantothenate kinase-associated neurodegeneration mouse model. 2442 15


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