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Patient homozygous for a recessive POLG mutation presents with features of MERRF

G Van Goethem1, R Mercelis, A Löfgren

  • 1Division of Neurology and the Neuromuscular Reference Center, University Hospital Antwerp, Belgium.

Neurology
|December 25, 2003
PubMed

Insights

Recessive mutations in the mitochondrial DNA polymerase gamma (POLG) gene can cause multisystem disorders. This study highlights a POLG mutation presenting with myoclonus, seizure, and neuropathy, mimicking MERRF syndrome without ophthalmoplegia.

Area of Science:

  • Genetics
  • Neuroscience
  • Mitochondrial Diseases

Background:

  • Progressive external ophthalmoplegia (PEO) is associated with dominant and recessive mutations in the mitochondrial DNA polymerase gamma (POLG) gene.
  • POLG is crucial for mitochondrial DNA replication and maintenance.

Observation:

  • A patient with a homozygous recessive missense mutation in POLG was identified.
  • The patient exhibited a multisystem disorder characterized by myoclonus, seizure, and sensory ataxic neuropathy.
  • Notably, the patient did not present with progressive external ophthalmoplegia (PEO).

Findings:

  • The clinical presentation strongly overlapped with the Myoclonus, Epilepsy, and Ragged Red Fibers (MERRF) syndrome.
  • This case demonstrates that POLG mutations can lead to PEO-absent phenotypes.

Implications:

  • Expanding the phenotypic spectrum associated with POLG mutations.
  • Suggests genetic testing for POLG in patients with MERRF-like syndromes.
  • Highlights the complex genotype-phenotype correlations in mitochondrial disorders.

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