RESUMO
We sequenced all genes of mitochondrial tRNAs of a patient with chronic progressive external ophthalmoplegia with 5% ragged red fibres and 15% COX-negative fibres but without macrorearrangements of mitochondrial DNA (mtDNA). Direct sequencing showed a novel heteroplasmic G>A substitution in position 12316 of tRNA(Leu(CUN)) gene. This change destroys a highly conserved G-C base coupling in tRNA TpsiC branch. By RFLP analysis we could demonstrate different degrees of heteroplasmy in different patient's tissues. This alteration, absent in a population of 110 patients with different encephalomyopathies, can be considered pathogenic: it is the tenth tRNA(Leu(CUN)) pathogenic mutation described up to date.
Assuntos
DNA Mitocondrial/genética , Mutação , Oftalmoplegia Externa Progressiva Crônica/genética , RNA de Transferência de Leucina/genética , Análise Mutacional de DNA , Feminino , Humanos , Pessoa de Meia-Idade , Músculo Esquelético/patologia , Oftalmoplegia Externa Progressiva Crônica/patologiaRESUMO
We report the case of a 41-year-old patient with bilateral hemorrhage of the thalamus, leading to death. Post-mortem examination showed acute myocarditis. Neuropathological study showed perivascular infiltrates in affected thalamic regions. Laboratory investigation failed to find any causal agent. We hypothesize an infective agent, affecting the heart and thalamus, as the cause of this syndrome. Diaschisis due to the strategic anatomical position of the thalamus may have been responsible for coma state and death.