Prevalence and progression of mitochondrial diseases: A study of 50 patients

Hospital Universitario Severo Ochoa, Madrid, Madrid, Spain
Muscle & Nerve (Impact Factor: 2.28). 12/2003; 28(6):690-5. DOI: 10.1002/mus.10507
Source: PubMed


We report 50 patients with various clinical phenotypes of mitochondrial disease studied over the past 10 years in a large urban area (Madrid Health Area 5). The clinical phenotypes showed a large variety of abnormalities in molecular biology and biochemistry. The prevalence of mitochondrial diseases was found to be 5.7 per 100,000 in the population over 14 years of age. Clinical and electrophysiological assessment reveal signs of neuropathy in 10 patients. Electromyographic findings consistent with myopathy were obtained in 37 cases. Six patients died of medical complications. Disease phenotype influenced survival to some degree (P < 0.01). Age of onset and gender were not associated with differences in survival. Mitochondrial disease is thus far more common than expected and a common cause of chronic morbidity.

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    • "Chronic progressive external ophthalmoplegia (CPEO) is one of the most common mitochondrial disorders in adults [1]. The characteristic clinical feature is a slowly progressive weakness of the extraocular muscles, resulting in ptosis and restriction of eye movements [5]. "
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    ABSTRACT: Chronic progressive external ophthalmoplegia (CPEO) is a relatively common mitochondrial disorder. Weakness of the extra-ocular, limb girdle and laryngeal muscles are established clinical features. Respiratory muscle involvement however has never been studied systematically, even though respiratory complications are one of the main causes of death. We therefore determined the prevalence and nature of respiratory muscle involvement in 23 patients with genetically confirmed CPEO. The main finding was decreased respiratory muscle strength, both expiratory (76.8% of predicted, p = 0.002) and inspiratory (79.5% of predicted, p = 0.004). Although the inspiratory vital capacity (92.5% of predicted, p = 0.021) and the forced expiratory volume in 1 s (89.3% of predicted, p = 0.002) were below predicted values, both were still within the normal range in the majority of patients. Expiratory weakness was associated with a decreased vital capacity (ρ = 0.502, p = 0.015) and decreased peak expiratory flow (ρ = 0.422, p = 0.045). Moreover, expiratory muscle strength was lower in patients with limb girdle weakness (62.6 ± 26.1% of predicted vs. 98.9 ± 22.5% in patients with normal limb girdle strength, p = 0.003), but was not associated with other clinical features, subjective respiratory complaints, disease severity or disease duration. Since respiratory involvement in CPEO is associated with severe morbidity and mortality, the present data justify periodic assessment of respiratory functions in all CPEO patients.
    Full-text · Article · May 2011 · Journal of Neurology
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    ABSTRACT: Mitochondria are organelles responsible for production of most energy through oxidative phosphorylation process (OXPHOS). It contains a double strand DNA (mitDNA) of about 16,500 bp encoding two ribosomal RNAs and 37 mitochondrial proteins. Mutation in mitDNA may result in multisystem syndromes known as mitochondrial diseases, affecting predominantly tissues that require high levels of ATP such as skeletal muscle (mitochondrial myopathies), brain (e.g. MELAS, MERRF, LHON e NARP), liver, kidney (Fanconi syndrome), heart and endocrine glands (Pearson syndrome). A case of mitochondrial disease was first reported in 1962 and correlation of such disease with mutations in mitDNA gained scientific importance in late 1980's. There are 150 alterations reported in mitDNA capable of producing metabolic dysfunctions of clinical relevance. To date, no standard protocol for diagnosis of mitochondrial diseases has been established, partially due to the wide amplitude of clinical manifestation generally observed. A combined analysis of clinical data, biochemical, morphological and laboratory tests must be performed to evaluate mitochondrial respiratory chain activity and integrity of nuclear and mitochondrial genomes. Currently, there are no effective treatments available for mitochondrial diseases, but only palliative therapeutics using conventional strategies to relieve symptoms. Thus, gene therapy emerges as potential therapeutic strategy for more efficient treatment of mitochondrial diseases.
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    ABSTRACT: The goal of this research is to improve the performance of NMR microscopy systems by fabricating the RF detection microcoil and preamplifier on a single monolithic GaAs substrate. The planar microcoil consists of 4-7 turns of gold conductor. A simple impedance matching network links the microcoil to a single stage, common source configuration, GaAs MESFET preamplifier
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