Studies conducted at University of Newcastle-upon-Tyne on dystonia recently published
2007 NOV 20 -- According to recent research from the United Kingdom, "In clinical practice, mitochondrial disease is seldom considered until a variable combination of seizures, alteration in tone, muscle weakness, and developmental problems is evident. However, it is not uncommon for one symptom to occur in isolation and dominate the clinical phenotype." "We report six patients from two families where dystonia was the principal clinical manifestation. A mitochondrial etiology was considered in each case because of the association of dystonia with other less prominent clinical features such as epilepsy Histochemical and biochemical analyses were undertaken in skeletal muscle biopsies from individuals in both families. Sequencing of skeletal muscle mtDNA was also performed and suspected mutations were quantified by hot last cycle PCR-RFLP or primer extension assay. Functional consequences of one of the mutations were investigated by measurement of steady state levels of mitochondrial tRNA Two distinct mitochondrial pathologies were identified: a novel, homoplasmic mitochondrial tRNACys (MTTC) mutation and the primary, m. 11778G >A Leber hereditary optic neuropathy (LHON) mutation. The mild nature of both mutations has permitted very high levels of mutated mtDNA to accumulate. Patients with the mutation in the MTTC gene have no wild type mtDNA detectable and although the LHON mutation is heteroplasmic in the patients we report, it is commonly observed to be homoplasmic The mitochondrial etiology identified in these patients emphasizes the pathologic potential of homoplasmic mutations and has important implications for the investigation and genetic counseling of families where dystonia is the principal clinical feature," wrote R. Mcfarland and colleagues, University of Newcastle-upon-Tyne. The researchers concluded: "We advocate that mitochondrial disease should be given serious consideration in patients with familial, progressive dystonia, particularly when additional neurologic features such as epilepsy are present." Mcfarland and colleagues published their study in Neurology (Homoplasmy, heteroplasmy, and mitochondrial dystonia. Neurology, 2007;69(9):911-916). For additional information, contact R. Mcfarland, University of Newcastle Upon Tyne, School Medical, School Neurology Neurobiology & Psychiatry, Mitochondrial Research Group, 4th Floor, Framlington Pl, Newcastle Upon Tyne NE2 4HH, Tyne & Wear, UK. Publisher contact information for the journal Neurology is: Lippincott Williams & Wilkins, 530 Walnut St., Philadelphia, PA 19106-3621, USA. Keywords: United Kingdom, Dystonia, University of Newcastle-upon-Tyne. This article was prepared by Life Science Weekly editors from staff and other reports. Copyright 2007, Life Science Weekly via NewsRx.com.
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