ubiquinone and Epilepsies--Myoclonic

Coenzyme Q10 (Q10) is available as an over-the-counter dietary supplement in the United States. While its use could be considered a form of alternative therapy, the medical profession has embraced the use of Q10 in specific disease states, including a series of neurologic and muscular diseases. Clinical laboratory monitoring is available for measurement of total Q10 in plasma and tissue and for measurement of redox status, ie, the ratio of reduced and oxidized forms of Q10. Many published studies have been anecdotal, in part owing to the rarity of some diseases involved. Unfortunately, many studies do not report Q10 levels, and, thus, the relationship of clinical response to Q10 concentration in plasma frequently is not discernible. Consistent laboratory monitoring of patients treated with this compound would help ease interpretation of the results of the treatment, especially because so many formulations of Q10 exist in the marketplace, each with its own bioavailability characteristics. Q10 has an enviable safety profile and, thus, is ideal to study as an adjunct to more conventional therapy. Defining patient subpopulations and characteristics that predict benefit from exogenous Q10 and defining therapeutic ranges for those particular applications are major challenges in this field.

Topics: Coenzymes; Epilepsies, Myoclonic; Friedreich Ataxia; Humans; Huntington Disease; Kearns-Sayre Syndrome; Mitochondrial Encephalomyopathies; Muscular Diseases; Nervous System Diseases; Parkinson Disease; Ubiquinone

Primary coenzyme Q10 (CoQ10) deficiencies are heterogeneous autosomal recessive disorders. CoQ2 mutations have been identified only rarely in patients. All affected individuals presented with nephrotic syndrome in the first year of life.. An infant is studied with myoclonic seizures and hypertrophic cardiomyopathy in the first months of life and developed a nephrotic syndrome in a later stage.. At three weeks of age, the index patient developed myoclonic seizures. In addition, he had hypertrophic cardiomyopathy and increased CSF lactate. A skeletal muscle biopsy performed at two months of age disclosed normal activities of the oxidative phosphorylation complexes. The child was supplemented with CoQ10 (5 mg/kg/day). At the age of four months, brain MR images showed bilateral increased signal intensities in putamen and cerebral cortex. After that age, he developed massive proteinuria. The daily dose of CoQ10 was increased to 30 mg/kg. Renal biopsy showed focal segmental glomerulosclerosis. Biochemical analyses of a kidney biopsy sample revealed a severely decreased activity of succinate cytochrome c reductase [complex II + III] suggesting ubiquinone depletion. Incorporation of labelled precursors necessary for CoQ10 synthesis was significantly decreased in cultured skin fibroblasts. His condition deteriorated and he died at the age of five months. A novel homozygous mutation c.326G > A (p.Ser109Asn) was found in COQ2.. In contrast to previously reported patients with CoQ2 the proband presented with early myoclonic epilepsy, hypertrophic cardiomyopathy and only in a later stage developed a nephrotic syndrome. The phenotype of this patient enlarges the phenotypical spectrum of the multisystem infantile variant.

Topics: Alkyl and Aryl Transferases; Ataxia; Cardiomyopathy, Hypertrophic; Diffusion Magnetic Resonance Imaging; Electroencephalography; Epilepsies, Myoclonic; Genetic Testing; Humans; Infant; Kidney; Magnetic Resonance Spectroscopy; Male; Microscopy, Electron, Transmission; Mitochondrial Diseases; Muscle Weakness; Muscle, Skeletal; Mutation; Nephrotic Syndrome; Ubiquinone