Subdural effusions and lack of early pontocerebellar hypoplasia in siblings with RARS2 mutations

Arch Dis Child. 2013 Dec;98(12):1004-7. doi: 10.1136/archdischild-2013-304308. Epub 2013 Sep 18.


Mutations in the recently described RARS2 gene encoding for mitochondrial arginyl-transfer RNA synthetase give rise to a disorder characterised by early onset seizures, progressive microcephaly and developmental delay. The disorder was named pontocerebellar hypoplasia type 6 (PCH6) based on the corresponding radiological findings observed in the original cases. We report two siblings with the RARS2 mutation who displayed typical clinical features of PCH6, but who had distinct neuroimaging features. Early scans showed marked supratentorial, rather than infratentorial, atrophy, and the pons remained preserved throughout. One sibling also had bilateral subdural effusions at presentation. The deceleration in head growth pointed to an evolving genetic/metabolic process giving rise to cerebral atrophy and secondary subdural effusions. RARS2 mutations should be considered in infants presenting with seizures, subdural effusions, decelerating head growth and evidence of cerebral atrophy even in the absence of pontocerebellar hypoplasia on imaging.

Keywords: Epilepsy; Microcephaly; Pontocerebellar Hypoplasia Type 6; RARS2; Subdural Effusion.

Publication types

  • Case Reports

MeSH terms

  • Arginine-tRNA Ligase / genetics*
  • Cerebellum / abnormalities*
  • Cerebellum / pathology
  • Diagnosis, Differential
  • Female
  • Humans
  • Infant
  • Male
  • Mutation
  • Olivopontocerebellar Atrophies / diagnosis
  • Olivopontocerebellar Atrophies / genetics*
  • Pons / abnormalities*
  • Pons / pathology
  • Siblings
  • Subdural Effusion / diagnosis
  • Subdural Effusion / genetics*
  • Subdural Effusion / pathology


  • Arginine-tRNA Ligase

Supplementary concepts

  • Pontocerebellar Hypoplasia Type 6