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)

We report a patient with late-onset celiac disease and neurological manifestations including myopathy, polyneuropathy, and ataxia. Laboratory investigations showed anti-gliadin antibodies and severe vitamin E deficiency. Muscle biopsy revealed inflammatory infiltrates and rimmed vacuoles, similar to those found in inclusion-body myositis. A gluten-free diet and vitamin E supplementation reversed both the clinical neurological manifestations and the abnormalities in the muscle biopsy. Anti-gliadin antibodies were no longer present. This case illustrates the spectrum of neurological complications of celiac disease and documents the occurrence of reversible pathology resembling inclusion-body myopathy in the muscle.
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PMID:Reversible inflammatory and vacuolar myopathy with vitamin E deficiency in celiac disease. 1538 48

Vitamin E is the most important lipid-soluble antioxidant in humans. Specific tocopherol-binding proteins favor the retention of the most potent vitamin E homologue, RRR-alpha-tocopherol (RRR-alpha-T) in man. The crystal structures of both the ligand-charged and the apo-forms of human alpha-tocopherol transfer protein (alpha-TTP) and of human supernatant protein factor (SPF) have been solved. The renewed interest in the biological function of tocopherol binders is based on the discovery of ataxia with vitamin E deficiency, a neurological disorder that is caused by genetic defects of the alpha-TTP gene and/or vitamin E deficiency. The analysis of the crystal structure of alpha-TTP provides the molecular basis of vitamin E retention in man. SPF has been reported to enhance cholesterol biosynthesis by facilitating the conversion of squalene to lanosterol. Nevertheless, the physiological role of SPF as well as its ligand specificity is not known. Investigations on the substrate specificity of SPF have uncovered binding of RRR-alpha-tocopherylquinone (RRR-alpha-TQ). RRR-alpha-TQ represents the major physiological oxidation product of RRR-alpha-T. The three-dimensional overlay of the ligand-charged structures of SPF and alpha-TTP indicates that ligand specificity in both proteins is mostly modulated by side-chain variations rather than by the backbone. Recent reports point towards the in vivo reduction of RRR-alpha-TQ to RRR-alpha-TQH(2) and its protective role in low-density lipoprotein oxidation. On the basis of these reports, it is proposed that SPF may enhance cholesterol biosynthesis indirectly by mediating the transfer of RRR-alpha-TQ to low-density lipoprotein, thus reducing oxidation of low-density lipoprotein and its subsequent cellular uptake by scavenger receptors.
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PMID:Molecular mechanisms of vitamin E transport. 1575 33

A 22-year-old man, with a past history of generalized tonic-clonic seizures treated with phenobarbital, presented with spinocerebellar ataxia. The electrophysiological studies revealed a demyelinating motor-sensory neuropathy. The serum vitamin E level was low. Sural nerve biopsy revealed loss of large myelinated fibers with evidence of remyelination. Vitamin E supplementation led to clinical and electrophysiological recovery of sensory conduction and evoked potentials. Motor nerve conduction, however, showed only partial recovery. Vitamin E deficiency leading to a demyelinating neuropathy, as in the present case, suggests that the full spectrum of the disease entity is not fully defined.
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PMID:Isolated vitamin E deficiency with demyelinating neuropathy. 1580 82

Although postgastrectomy vitamin E deficiency rarely occurs, it can cause neuromuscular disorder such as neuropathy, myopathy and cerebellar ataxia. We encounter a lot of cases whose serum vitamin E level were decreased after gastrectomy. We evaluated the oral vitamin E intake as a therapy to these cases. The subjects of this study were 11 gastrectomized patients (8 patients had total gastrectomy, 2 subtotal gastrtectomy, 1 partial gastrectomy) with decreased vitamin E. 10 patients had neurological complications such as dizziness, dysesthesia, truncal ataxia. Serum vitamin E increased to normal level in 10 patients and neurological disturbances were improved in 9 patients. The minimum requirement of oral vitamin E intake was 150 mg a day for normalization of serum vitamin E, on the other hand, it decreased with 150 mg intake in some patients. Their serum level increased with 300 mg. We suggest that it is important to check serum vitamin E in gastrectomized patients and oral vitamin E should be supplied over 300 mg for the therapy with vitamin E deficiency.
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PMID:[Treatment of neurological complication due to postgastrectomy vitamin E deficiency]. 1585 61

Ataxia with vitamin E deficiency (AVED) is an autosomal recessive disease characterized clinically by neurological symptoms with often striking resemblance to those of Friedreich's ataxia (FA). Molecular analysis is needed for an early differential diagnosis, in order to initiate therapeutic vitamin E supplementation before damage develops. We studied 16 patients from seven Moroccan families presenting an autosomal recessive Friedreich-like ataxia with vitamin E deficiency. Our patients were homozygous for 744 del A mutation of alpha-TTP gene. Compilation of clinical records revealed a great phenotypic variability and some features indicating a new possible role of vitamin E in hypothalamo-hypophysial system regulation and cardiomyopathy prevention. Early vitamin E supplementation may provide considerable improvement of neurological signs and other associated abnormalities. Clinical heterogeneity is for involvement of other non-genetic defect and indicated another role of vitamin E, which should be better studied.
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PMID:Vitamin E deficiency ataxia with (744 del A) mutation on alpha-TTP gene: genetic and clinical peculiarities in Moroccan patients. 1595 2

A 12-year-old boy with mental retardation, obesity, ataxia, and visual impairment was shown to have normal fasting plasma triglyceride but low cholesterol and vitamin E levels. Investigations indicated that he was compound heterozygous for two mutations in the apolipoprotein B gene (APOB), resulting in a failure to express apolipoprotein B-100, yet retain apolipoprotein B-48 production. The proband therefore was able to form chylomicrons, but not a low-density lipoprotein capable of receptor-mediated endocytosis. This resulted in chronic vitamin E deficiency. We suggest the term normotriglyceridemic hypobetalipoproteinemia for this easily recognizable condition.
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PMID:Mental retardation and ataxia due to normotriglyceridemic hypobetalipoproteinemia. 1598 16

The tocopherol transfer protein (TTP) is a member of the CRAL-TRIO family of lipid binding proteins that facilitates vitamin E transfer between membrane vesicles in vitro. In cultured hepatocytes, TTP enhances the secretion of tocopherol to the media; presumably, tocopherol transfer is at the basis of this biological activity. The mechanism underlying ligand transfer by TTP is presently unknown, and available tools for monitoring this activity suffer from complicated assay procedure and poor sensitivity. We report the characterization of a fluorescent vitamin E analogue, (R)-2,5,7,8-tetramethylchroman-2-[9-(7-nitrobenz[1,2,5]oxadiazol-4-ylamino)nonyl]chroman-6-ol (NBD-TOH), as a sensitive and convenient probe for the ligand binding and transfer activities of TTP. Upon binding to TTP, NBD-TOH fluorescence is blue shifted, and its intensity is greatly enhanced. We used these properties to accurately determine the affinity of NBD-TOH to TTP. The analogue binds to TTP reversibly and with high affinity (K(d) = 8.5 +/- 6 nM). We determined the affinity of NBD-TOH to a TTP protein in which lysine 59 is replaced with a tryptophan. When occurring in humans, this heritable mutation causes the ataxia with vitamin E deficiency (AVED) disorder. We find that the affinity of NBD-TOH to this mutant TTP is greatly diminished (K(d) = 71 +/- 19 nM). NBD-TOH functioned as a sensitive fluorophore in fluorescent resonance energy transfer (FRET) experiments. Using the fluorescent lipids TRITC-DHPE or Marina Blue-DHPE as a donor or an acceptor for NBD-TOH fluorescence, we obtained high-resolution kinetic data for tocopherol movement out of lipid bilayers, a key step in the TTP-facilitated ligand transfer reaction.
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PMID:Utility of a fluorescent vitamin E analogue as a probe for tocopherol transfer protein activity. 1643 Feb 3

Alpha-, beta-, gamma- and delta-tocopherol are present in many foods and are, in the absence of fat malabsorption, well absorbed from the gut. Their anti-oxidant property is well known and protects arteries and capillaries as well as blood lipids and nervous tissue against oxidative stress. In contrast to beta-, gamma- and delta-tocopherol, alpha-tocopherol is preferentially conserved by the discriminating action of the liver alpha-tocopherol transfer protein, which also maintains plasma alpha-tocopherol concentration within a range of 20 to 40 microM. In the circulation, alpha-tocopherol, in association with the transfer-protein, is assembled into the very low-density lipoprotein and low-density lipoprotein particles and released for use by the peripheral tissues. Recent data suggest that alpha-tocopherol is not only an anti-oxidant but also a regulator of gene expression through its binding to nuclear receptors. The precise mechanism of regulating gene expression, however, is still unknown. The four tocopherols are ultimately degraded by omega-oxidation and subsequent beta-oxidations followed by the elimination of the metabolites in the bile and in the urine. Patients with a defect of the alpha-tocopherol transfer protein are unable to maintain their alpha-tocopherol reserves and progressively lose tendon reflexes and have signs and symptoms of spinocerebellar ataxia while plasma vitamin E level drops below 2 microg/ml.
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PMID:Recent advances in vitamin E metabolism and deficiency. 1649 83

Tocopherol transfer protein (TTP) regulates vitamin E status by facilitating the secretion of tocopherol from liver to circulating lipoproteins. Heritable mutations in the ttpA gene, encoding for TTP, result in ataxia with vitamin E deficiency (AVED) syndrome, typified by low vitamin E levels and a plethora of neurological disorders. The molecular mechanisms by which TTP facilitates tocopherol secretion are presently unknown. We recently showed that vitamin E is taken up by hepatocytes through an endocytic process and that, shortly following uptake, the vitamin is found primarily in lysosomes. We showed further that TTP is localized to late endocytic vesicles and that it facilitates the intracellular trafficking of tocopherol from lysosomes to the plasma membrane. To gain insight into the molecular mechanisms that underlie TTP actions, we studied the physiological impact of three naturally occurring heritable mutations in the ttpA gene (the R59W, R221W, and A120T substitutions). We found that these mutations impair the ability of TTP to facilitate the secretion of vitamin E from cells. Furthermore, the degree of impairment corresponded to the severity of the AVED pathology associated with each mutation. In cells that express mutated TTP proteins, vitamin E did not traffic to the plasma membrane and remained "trapped" in lysosomes. In addition, we observed that substitution mutations that cause the AVED syndrome impart a marked instability on the TTP protein. These observations suggest that the physiological role of TTP is anchored in its ability to direct vitamin E trafficking from the endocytic compartment to transport vesicles that deliver the vitamin to the site of secretion at the plasma membrane.
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PMID:Biochemical consequences of heritable mutations in the alpha-tocopherol transfer protein. 1681 22

We present a 36-year-old Dutch woman who suffered from a progressive form of cerebellar ataxia since school age. In her childhood she was diagnosed with Friedreich's ataxia. Genetic analysis of the frataxin gene at 34 years of age, however, had revealed no abnormal GAA triplet expansion. We identified two point mutations in the alpha-tocopherol transport protein (alpha-TTP) gene on chromosome 8q13, and the diagnosis ataxia with isolated vitamin E deficiency (AVED) was made. This report illustrates the diagnosis AVED and its relation to vitamin E metabolism. It is important to evaluate previously made diagnoses when newly developed tests can be performed for confirmation.
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PMID:First case of ataxia with isolated vitamin E deficiency in the Netherlands. 1704 53


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