A novel de novo mutation of the mitochondrial tRNAlys gene mt.8340G>a associated with pure myopathy.
Most patients with mutations in the tRNA(lys) gene (MTTK) present with symptoms from the central nervous system (CNS). We describe a 41-year-old woman with pure myopathy associated with a novel de novo mtDNA mutation, mt.8340G>A, which was heteroplasmic in muscle (53%), blood, urine and mouth epithelial cells (<7%). No other family members, including her mother, carried the mutation. She presented with exercise intolerance from age 9, and since age 20 she experienced ptosis and reduced ocular motility. A muscle biopsy revealed ragged red fibres (10%), no COX negative fibres, and many fibres with central nuclei (30%), indicating ongoing damage and repair. The present case expands the mutational and phenotypic spectrum of diseases associated with mutations in MTTK.
['Jeppesen|Tina Dysgaard|TD|', 'Duno|Morten|M|', 'Risom|Lotte|L|', 'Wibrand|Flemming|F|', 'Rafiq|Jabin|J|', 'Krag|Thomas|T|', 'Jakobsen|Johannes|J|', 'Andersen|Henning|H|', 'Vissing|John|J|']
D000328:Adult D001483:Base Sequence D059018:DNA Contamination D004272:DNA, Mitochondrial D005260:Female D006801:Humans D008969:Molecular Sequence Data D018482:Muscle, Skeletal D009135:Muscular Diseases D010375:Pedigree D017354:Point Mutation D012357:RNA, Transfer, Lys
tRNA(lys) MTTK gene Mitochondrial DNA Novel mutation