Electrophysiologic features of abetalipoproteinemia

Brin, Mitchell F.; Pedley, Timothy A.; Lovelace, Robert E.; Emerson, Ronald G.; Gouras, Peter; MacKay, Cynthia J.; Kayden, Herbert J.; Levy, Joseph; Baker, Herman

doi:10.1212/wnl.36.5.669

Cited by 71 publications

(9 citation statements)

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“…Electrophysiological studies usually demonstrate absent or low‐amplitude sensory nerve action potentials. Motor nerve conduction studies are typically normal,4, 9–11 but reduced CMAP amplitude and mildly slowed conduction velocity have been reported 12, 14, 24. Needle electromyography is normal or shows changes suggestive of mild denervation.…”

Section: Discussionmentioning

confidence: 99%

Isolated vitamin E deficiency with demyelinating neuropathy

et al. 2005

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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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Section: Discussionmentioning

confidence: 99%

Isolated vitamin E deficiency with demyelinating neuropathy

et al. 2005

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“…AnnualReviews.org, Electronic Materials). Although the clinical course is variable without treatment, it leads progressively to impaired mobility, and some patients require a wheelchair, or they become effectively bedridden (32,36,64,100,135,177,195,203,212). Although the clinical course is variable without treatment, it leads progressively to impaired mobility, and some patients require a wheelchair, or they become effectively bedridden (32,36,64,100,135,177,195,203,212).…”

Section: Neurological Signsmentioning

confidence: 99%

The Role of the Microsomal Triglygeride Transfer Protein in Abetalipoproteinemia

et al. 2000

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The microsomal triglyceride transfer protein (MTP) is a dimeric lipid transfer protein consisting of protein disulfide isomerase and a unique 97-kDa subunit. In vitro, MTP accelerates the transport of triglyceride, cholesteryl ester, and phospholipid between membranes. It was recently demonstrated that abetalipoproteinemia, a hereditary disease characterized as an inability to produce chylomicrons and very low-density lipoproteins in the intestine and liver, respectively, results from mutations in the gene encoding the 97-kDa subunit of the microsomal triglyceride transfer protein. Downstream effects resulting from this defect include malnutrition, very low plasma cholesterol and triglyceride levels, altered lipid and protein compositions of membranes and lipoprotein particles, and vitamin deficiencies. Unless treated, abetalipoproteinemic subjects develop gastrointestinal, neurological, ophthalmological, and hematological abnormalities.

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“…(1). One form, α‐tocopherol, is the most abundant form in nature (2), has the highest biological activity based on fetal resorption assays (3–5), and reverses vitamin E deficiency symptoms in humans (6–10). The molecular functions fulfilled specifically by α‐tocopherol have yet to be fully described, but it is unlikely they are limited to general antioxidant functions.…”

Section: Introductionmentioning

confidence: 99%

Vitamin E: function and metabolism

1999

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Although vitamin E has been known as an essential nutrient for reproduction since 1922, we are far from understanding the mechanisms of its physiological functions. Vitamin E is the term for a group of tocopherols and tocotrienols, of which alpha-tocopherol has the highest biological activity. Due to the potent antioxidant properties of tocopherols, the impact of alpha-tocopherol in the prevention of chronic diseases believed to be associated with oxidative stress has often been studied, and beneficial effects have been demonstrated. Recent observations that the alpha-tocopherol transfer protein in the liver specifically sorts out RRR-alpha-tocopherol from all incoming tocopherols for incorporation into plasma lipoproteins, and that alpha-tocopherol has signaling functions in vascular smooth muscle cells that cannot be exerted by other forms of tocopherol with similar antioxidative properties, have raised interest in the roles of vitamin E beyond its antioxidative function. Also, gamma-tocopherol might have functions apart from being an antioxidant. It is a nucleophile able to trap electrophilic mutagens in lipophilic compartments and generates a metabolite that facilitates natriuresis. The metabolism of vitamin E is equally unclear. Excess alpha-tocopherol is converted into alpha-CEHC and excreted in the urine. Other tocopherols, like gamma- and delta-tocopherol, are almost quantitatively degraded and excreted in the urine as the corresponding CEHCs. All rac alpha-tocopherol compared to RRR-alpha-tocopherol is preferentially degraded to alpha-CEHC. Thus, there must be a specific, molecular role of RRR-alpha-tocopherol that is regulated by a system that sorts, distributes, and degrades the different forms of vitamin E, but has not yet been identified. In this article we try to summarize current knowledge on the function of vitamin E, with emphasis on its antioxidant vs. other properties, the preference of the organism for RRR-alpha-tocopherol, and its metabolism to CEHCs.

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Electrophysiologic features of abetalipoproteinemia

Cited by 71 publications

References 0 publications

Isolated vitamin E deficiency with demyelinating neuropathy

Isolated vitamin E deficiency with demyelinating neuropathy

The Role of the Microsomal Triglygeride Transfer Protein in Abetalipoproteinemia

Vitamin E: function and metabolism

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