A double mutation (A8296G and G8363A) in the mitochondrial DNA tRNALys gene associated with myoclonus epilepsy with ragged-red fibers

Neurology ◽  
1999 ◽  
Vol 52 (2) ◽  
pp. 377-377 ◽  
Author(s):  
J. Arenas ◽  
Y. Campos ◽  
B. Bornstein ◽  
R. Ribacoba ◽  
M. A. Martin ◽  
...  
Keyword(s):  
Mitochondrial Dna ◽  
Double Mutation ◽  
Ragged Red Fibers ◽  
Myoclonus Epilepsy

Myoclonus epilepsy and ragged-red fibers: blood mitochondrial DNA heteroplasmy in affected and asymptomatic members of a family

1993 ◽  
Vol 88 (6) ◽  
pp. 406-409 ◽  
Author(s):  
G. Piccolo ◽  
F. Focher ◽  
A. Verri ◽  
S. Spadari ◽  
P. Banfi ◽  
...  
Keyword(s):  
Mitochondrial Dna ◽  
Ragged Red Fibers ◽  
Myoclonus Epilepsy ◽  
Mitochondrial Dna Heteroplasmy

Bilateral Putaminal Necrosis Associated With the Mitochondrial DNA A8344G Myoclonus Epilepsy With Ragged Red Fibers (MERRF) Mutation: An Infantile Case

2006 ◽  
Vol 21 (1) ◽  
pp. 79-82 ◽  
Author(s):  
Simona Orcesi ◽  
Ksenija Gorni ◽  
Cristiano Termine ◽  
Carla Uggetti ◽  
Pierangelo Veggiotti ◽  
...  
Keyword(s):  
Mitochondrial Dna ◽  
Ragged Red Fibers ◽  
Myoclonus Epilepsy

scholarly journals In vitro analysis of mutations causing myoclonus epilepsy with ragged-red fibers in the mitochondrial tRNA(Lys)gene: two genotypes produce similar phenotypes.

1995 ◽  
Vol 15 (5) ◽  
pp. 2872-2881 ◽  
Author(s):  
J P Masucci ◽  
M Davidson ◽  
Y Koga ◽  
E A Schon ◽  
M P King
Keyword(s):  
Protein Synthesis ◽  
Molecular Genetic ◽  
Mitochondrial Disorder ◽  
Morphological Characteristics ◽  
Mitochondrial Translation ◽  
Mitochondrial Trna ◽  
Mtdna Mutations ◽  
Ragged Red Fibers ◽  
Myoclonus Epilepsy

Cytoplasts from patients with myoclonus epilepsy with ragged-red fibers harboring a pathogenic point mutation at either nucleotide 8344 or 8356 in the human mitochondrial tRNA(Lys) gene were fused with human cells lacking endogenous mitochondrial DNA (mtDNA). For each mutation, cytoplasmic hybrid (cybrid) cell lines containing 0 or 100% mutated mtDNAs were isolated and their genetic, biochemical, and morphological characteristics were examined. Both mutations resulted in the same biochemical and molecular genetic phenotypes. Specifically, cybrids containing 100% mutated mtDNAs, but not those containing the corresponding wild-type mtDNAs, exhibited severe defects in respiratory chain activity, in the rates of protein synthesis, and in the steady-state levels of mitochondrial translation products. In addition, aberrant mitochondrial translation products were detected with both mutations. No significant alterations were observed in the processing of polycistronic RNA precursor transcripts derived from the region containing the tRNA(Lys) gene. These results demonstrate that two different mtDNA mutations in tRNA(Lys), both associated with the same mitochondrial disorder, result in fundamentally identical defects at the cellular level and strongly suggest that specific protein synthesis abnormalities contribute to the pathogenesis of myoclonus epilepsy with ragged-red fibers.

scholarly journals The protective roles of phosphorylated heat shock protein 27 in human cells harboring myoclonus epilepsy with ragged-red fibers A8344G mtDNA mutation

FEBS Journal ◽  
2012 ◽  
Vol 279 (16) ◽  
pp. 2987-3001 ◽  
Author(s):  
Hsueh-Fu Chen ◽  
Chin-Yi Chen ◽  
Ting-Hui Lin ◽  
Zhao-Wei Huang ◽  
Tang-Hao Chi ◽  
...  
Keyword(s):  
Heat Shock ◽  
Heat Shock Protein ◽  
Heat Shock Protein 27 ◽  
Human Cells ◽  
Mtdna Mutation ◽  
Ragged Red Fibers ◽  
Myoclonus Epilepsy

scholarly journals When should MERRF (myoclonus epilepsy associated with ragged-red fibers) be the diagnosis?

2014 ◽  
Vol 72 (10) ◽  
pp. 803-811 ◽  
Author(s):  
Paulo José Lorenzoni ◽  
Rosana Herminia Scola ◽  
Cláudia Suemi Kamoi Kay ◽  
Carlos Eduardo S. Silvado ◽  
Lineu Cesar Werneck
Keyword(s):  
Muscle Biopsy ◽  
Morphological Changes ◽  
Mitochondrial Disorder ◽  
Point Mutations ◽  
Clinical Manifestations ◽  
Strong Reaction ◽  
Brain Images ◽  
Ragged Red Fibers ◽  
Myoclonus Epilepsy ◽  
Generalized Epilepsy

Myoclonic epilepsy associated with ragged red fibers (MERRF) is a rare mitochondrial disorder. Diagnostic criteria for MERRF include typical manifestations of the disease: myoclonus, generalized epilepsy, cerebellar ataxia and ragged red fibers (RRF) on muscle biopsy. Clinical features of MERRF are not necessarily uniform in the early stages of the disease, and correlations between clinical manifestations and physiopathology have not been fully elucidated. It is estimated that point mutations in the tRNALys gene of the DNAmt, mainly A8344G, are responsible for almost 90% of MERRF cases. Morphological changes seen upon muscle biopsy in MERRF include a substantive proportion of RRF, muscle fibers showing a deficient activity of cytochrome c oxidase (COX) and the presence of vessels with a strong reaction for succinate dehydrogenase and COX deficiency. In this review, we discuss mainly clinical and laboratory manifestations, brain images, electrophysiological patterns, histology and molecular findings as well as some differential diagnoses and treatments.

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