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)

Familial hemiplegic migraine (FHM) is an autosomal dominant subtype of migraine with hemiparesis during the aura. In over 50% of cases the causative gene is CACNA1A (FHM1), which in some cases produces a phenotype with cerebellar signs, including ataxia and nystagmus. Recently, mutations in ATP1A2 on chromosome 1q23 encoding a Na+/K+ -ATPase subunit were identified in four families (FHM2). We now describe an FHM2 pedigree with a fifth ATP1A2 mutation coding for a G301R substitution. The phenotype was particularly severe and included hemiplegic migraine, seizure, prolonged coma, elevated temperature, sensory deficit, and transient or permanent cerebellar signs, such as ataxia, nystagmus, and dysarthria. A mild crossed cerebellar diaschisis during an attack further supported the clinical evidence of a cerebellar deficit. This is the first report suggesting cerebellar involvement in FHM2. A possible role for CACNA1A in producing the phenotype in this family was excluded by linkage studies to the FHM1 locus. The study of this family suggests that the absence of cerebellar signs may not be a reliable indicator to clinically differentiate FHM2 from FHM1.
 ...
PMID:A G301R Na+/K+ -ATPase mutation causes familial hemiplegic migraine type 2 with cerebellar signs. 1545 25

Recent advances in the studies of the genetic liability to migraine include the discovery of two genes responsible for familial hemiplegic migraine (FHM) and the analysis of several sites of linkage or genetic association for the so-called typical migraines, e. g., migraine with (MA) and without aura (MO). The 2 genes implicated in the genetics of FHM are CACNA1A for FHM1 and ATP1A2 for FHM2. It is still unclear how dysfunction in these genes may trigger attacks of migraine with hemiplegic features and, in at least part of the families with FHM, also paroxysmal or progressive ataxia and epileptic seizures. It appears that mutations in CACNA1A responsible for FHM1 alter calcium influx and calcium currents in neurons, possible factors of spreading depression like events. On the other hand, abnormal regulation of intracellular calcium concentrations could alter neurotransmitter release and other cellular functions. In the case of ATP1A2 mutations, haplo-insufficiency of the gene has been hypothesised to result in abnormal potassium level regulation because of faulty Na/K exchange with subsequent depolarisation and increased liability to spreading depression, or/and in abnormal calcium levels because of the concomitant activation of the Na/Ca exchanger, with a mechanism therefore comparable to that at work in FHM1. Much more work is clearly necessary to elucidate these pathophysiological mechanisms; advances in genetics however may represent important steps in the clarification of the physiopathology of the migraine attack.
 ...
PMID:The physiopathology of migraine: the contribution of genetics. 1554 78

Spinocerebellar ataxia type 6 (SCA6) is a neurodegenerative, monogenic, and autosomic dominant disease which is characterized by a global cerebellar atrophy. Typically the onset is at mature age and undergoes a moderate evolution. This illness has been associated with a mutation in the gene CACNA1A, that encodes for subunit alpha1A of P/Q type voltage/dependent calcium channel. The mutation results in the expansion of a CAG triplet repeat located in the last exon of the gene, which is translated into a polyglutamine chain in the carboxyl tail of the calcium channel subunit. Several studies have been made to clarify the mechanism for the toxicity of polyglutamines in cerebellar neurons; SCA6 could be considered a polyglutamine proteinopathy linked to caspases mediated death pathway. However, SCA6 is also considered a channelopathy, like paroxysmal diseases as hemiplegic familiar migraine and episodic ataxia type 2. The goal of this review is to analyze the intracellular mechanism triggering neuronal death in cerebellum, and the subsequent neurodegeneration.
 ...
PMID:[Molecular physiopathology of the spinocerebellar ataxia type 6 (SCA6)]. 1561 20

Complex forms of hereditary spastic paraplegia (HSP) are rare and usually transmitted in an autosomal recessive pattern. A family of four generations with autosomal dominant hereditary spastic paraplegia (AD-HSP) and a complex phenotype with variably expressed co-existing ataxia, dysarthria, unipolar depression, epilepsy, migraine, and cognitive impairment was investigated. Genetic linkage analysis and sequencing of the SPG4 gene was performed and electrophysiologic investigations were carried out in six individuals and positron emission tomography (PET) in one patient. The disease was linked to the SPG4 locus on chromosome 2p as previously reported for pure HSP. Sequence analysis of the SPG4 (spastin) gene identified a novel 1593 C > T (GLN490Stop) mutation leading to premature termination of exon 12 with ensuing truncation of the encoded protein. However, the mutation was only identified in those individuals who were clinically affected by a complex phenotype consisting of HSP and cerebellar ataxia. Other features noted in this kindred including epilepsy, cognitive impairment, depression, and migraine did not segregate with the HSP phenotype or mutation, and therefore the significance of these features to SPG4 is unclear. Electrophysiologic investigation showed increased central conduction time at somatosensory evoked potentials measured from the lower limbs as the only abnormal finding in two affected individuals with the SPG4 mutation. Moreover, PET of one patient showed significantly relatively decreased regional cerebral blood flow in most of the cerebellum. We conclude that this kindred demonstrates a considerable overlap between cerebellar ataxia and spastic paraplegia, emphasizing the marked clinical heterogeneity of HSP associated with spastin mutations.
 ...
PMID:Hereditary spastic paraplegia with cerebellar ataxia: a complex phenotype associated with a new SPG4 gene mutation. 1566 12

Familial hemiplegic migraine (FHM) is an autosomal dominant disorder characterized by transient hemiplegia followed by migraine headache, and recently approximately half of FHM families have been elucidated to be caused by mis-sense mutations in P/Q-type Ca channel alpha(1)-subunit gene (CACNA1A). This subunit forms channel pore and is implicated in the regulation of membrane excitability as voltage sensor, therefore FHM is thought to be channelopathy. The CACNA1A gene is causative of episodic ataxia type-2 and of spinocerebellar atrophy type 6. Moreover, FHM with cerebellar ataxia is only associated with the mutation in CACNA1A, dysfunction of the calcium channel may cause cerebellar degeneration. New genotype and phenotype have been reported, more reports and analyses are expected.
 ...
PMID:[Familial hemiplegic migraine]. 1577 64

Celiac disease (CD) long has been associated with neurologic and psychiatric disorders including cerebellar ataxia, peripheral neuropathy, epilepsy, dementia, and depression. Earlier reports mainly have documented the involvement of the nervous system as a complication of prediagnosed CD. However, more recent studies have emphasized that a wider spectrum of neurologic syndromes may be the presenting extraintestinal manifestation of gluten sensitivity with or without intestinal pathology. These include migraine, encephalopathy, chorea, brain stem dysfunction, myelopathy, mononeuritis multiplex, Guillain-Barre-like syndrome, and neuropathy with positive antiganglioside antibodies. The association between most neurologic syndromes described and gluten sensitivity remains to be confirmed by larger epidemiologic studies. It further has been suggested that gluten sensitivity (as evidenced by high antigliadin antibodies) is a common cause of neurologic syndromes (notably cerebellar ataxia) of otherwise unknown cause. Additional studies showed high prevalence of gluten sensitivity in genetic neurodegenerative disorders such as hereditary spinocerebellar ataxia and Huntington's disease. It remains unclear whether gluten sensitivity contributes to the pathogenesis of these disorders or whether it represents an epiphenomenon. Studies of gluten-free diet in patients with gluten sensitivity and neurologic syndromes have shown variable results. Diet trials also have been inconclusive in autism and schizophrenia, 2 diseases in which sensitivity to dietary gluten has been implicated. Further studies clearly are needed to assess the efficacy of gluten-free diet and to address the underlying mechanisms of nervous system pathology in gluten sensitivity.
 ...
PMID:Neurologic presentation of celiac disease. 1582 33

In the past few years several spontaneous or engineered mouse models with mutations in Ca2+ channel genes have become available, providing a powerful approach to defining Ca2+ channel function in vivo. There have been recent advances in outlining the phenotypes and in the functional analysis of mouse models with mutations in genes encoding the pore-forming subunits of Ca(V)2.1 (P/Q-type), Ca(V)2.2 (N-type) and Ca(V)2.3 (R-type) Ca2+ channels, the channels involved in controlling neurotransmitter release at mammalian synapses. These data indicate that Ca(V)2.1 channels have a dominant and efficient specific role in initiating fast synaptic transmission at central excitatory synapses in vivo, and suggest that the Ca(V)2.1 channelopathies are primarily synaptic diseases. The different disorders probably arise from disruption of neurotransmission in specific brain regions: the cortex in the case of migraine, the thalamus in the case of absence epilepsy and the cerebellum in the case of ataxia.
 ...
PMID:Function and dysfunction of synaptic calcium channels: insights from mouse models. 1592 81

Voltage-gated calcium channels are key sources of calcium entry into the cytosol. Mutations in calcium channels have been implicated in numerous disorders such as migraine, incomplete congenital X-linked stationary night blindness, epilepsy, and ataxia, and they are important therapeutic targets for the treatment of pain, stroke, hypertension, and epilepsy. Calcium channel antagonists can be broadly classified into three groups. 1) Inorganic ions typically nonselectively block the pore of most calcium channel subtypes, and in some cases, alter gating kinetics. 2) Peptides isolated from arachnids, cone snails, and snakes frequently selectively antagonize individual calcium channel subtypes by direct occlusion of the pore or altering gating kinetics. 3) Small organic molecules of various structure-activity-relationship (SAR) classes can mediate both selective and nonselective effects on individual calcium channel subtypes, and occlude the pore or reduce channel availability. Here, we provide an overview of classes of inhibitors of non-L-type calcium channels.
 ...
PMID:Molecular pharmacology of non-L-type calcium channels. 1597 66

Basilar-type migraine (BTM) is a type of migraine with aura symptoms resulting from brain stem or bi-hemispheric structures but without motor elements. There are no precise data on the frequency of BTM. The main cohort of the patients includes young people and children with female predomination. The onset of the disease usually occurs before the age of 25. The diagnosis of BTM is based on the finding of two migraine attacks accompanied by a specific aura, with dysarthria, vertigo, tinnitus, impaired hearing, double vision, visual aura elements, ataxia of a cerebellar type, loss of consciousness, and bilateral paresthesias. In the differential diagnosis one should consider the pathology of posterior fossa, diseases with recurrent vertigo, complex epileptic seizures, CADASIL and MELAS syndromes, and alternative hemiplegic migraine with cerebellar symptoms and signs. In the prophylaxis sodium valproate and calcium-entry blockers and, especially in the prophylaxis of vertigo, betahistine chloride are used.
 ...
PMID:[Basilar-type migraine: pathophysiology, symptoms and signs, and treatment]. 1641 73

Scores of monogenic Mendelian ion channel diseases serve to anchor the pathophysiology of the channelopathies, but there are also now clear examples of environmental, pharmacogenetic, and acquired channelopathy mechanisms. The cardinal feature of heritable ion channel disease is a periodic disturbance of rhythmic function in constitutionally hyperexcitable tissue. While the complexity of neuroanatomy obscures functional analysis of mutations causing monogenic seizure, ataxia, or migraine syndromes, extrapolation from the cardiac (Long QT [LQT]) and muscle (Periodic Paralysis) channelopathy syndromes provides a simplified predictive framework of molecular pathology: electrically stabilizing potassium ion (K(+)) and chloride ion (Cl(-)) channels, likely having lesions that diminish their current, and excitatory Na(+) channels, likely having gain-of-function lesions. The voltage-gated calcium channel gene family that contains CACNA1C, the newest LQT locus, causing Timothy Syndrome with a phenotype including autism, has proven to be particularly informative for its members' ability to tie the various central nervous system (CNS) phenotypes together in an interpretable fashion, now including direct extension to the classically multigenic neuropsychiatric phenotypes. Features of a promising ion channel candidate gene arise from its broad locus, gene family, nature of alleles, physiology and pharmacology, tissue expression profile, and phenotype in model organisms. KCNN3 is explored as a paradigm to consider.
 ...
PMID:Ion channel functional candidate genes in multigenic neuropsychiatric disease. 1649 76


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>