MELAS phenotype associated with m.3302A>G mutation in mitochondrial tRNA(Leu(UUR)) gene

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Masahide Goto1, Hirofumi Komaki1, Takashi Saito1

  • 1Department of Child Neurology, National Center Hospital, National Center of Neurology and Psychiatry, Tokyo, Japan.

Brain & Development
|April 16, 2013
PubMed

Insights

The m.3302A>G mitochondrial mutation causes slowly progressive myopathy. A new case revealed stroke-like episodes and unique strongly SDH reactive blood vessels, expanding the mutation's known effects.

Area of Science:

  • Genetics
  • Neurology
  • Mitochondrial Diseases

Background:

  • The m.3302A>G mutation in mitochondrial tRNA(Leu(UUR)) is rare, linked to adult-onset myopathy.
  • Previous cases showed slowly progressive muscle weakness and mild CNS involvement.

Observation:

  • An 11-year-old boy presented with progressive muscle weakness starting at age 7.
  • He experienced recurrent stroke-like episodes by age 10, leading to a MELAS diagnosis.
  • Muscle biopsy revealed the m.3302A>G mutation and unique strongly SDH reactive blood vessels (SSVs).

Findings:

  • The patient's heteroplasmic m.3302A>G mutation was identified through mitochondrial gene analysis.
  • The presence of SSVs, previously unobserved in m.3302A>G-related myopathies, was a key histological finding.

Implications:

  • This case expands the known phenotypic spectrum of the m.3302A>G mitochondrial mutation.
  • It highlights the importance of considering MELAS and associated vascular changes in pediatric myopathies.
  • Further research into SSVs in mitochondrial disorders is warranted.
Keywords:
MELASMyopathym.3302A>G mutation

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