Infantile-onset spinocerebellar ataxia type 5 associated with a novel SPTBN2 mutation: A case report

Brain Dev. 2019 Aug;41(7):630-633. doi: 10.1016/j.braindev.2019.03.002. Epub 2019 Mar 18.


Background: Spinocerebellar ataxia type 5 (SCA5), a dominant spinocerebellar ataxia is caused by spectrin beta nonerythrocytic 2 gene (SPTBN2) mutation. It typically consists of a slow progressive cerebellar ataxia with an onset principally in adulthood. Here, we report on the first Japanese patient with infantile-onset SCA5 associated with a novel heterozygous SPTBN2 mutation.

Case report: The patient, a 6-year-old girl, developed delayed motor development and unsteady arm movement during infancy. She also showed gaze-evoked nystagmus, saccadic eye pursuit, dysarthria, dysmetria, intention tremor and mild intellectual disability. Brain MRI revealed moderate cerebellar atrophy and mild pontine atrophy. Comprehensive target capture sequencing to identify the causative gene identified a novel missense mutation in SPTBN2 (c.1309C<G, p.R437G), which was thought to be pathogenic.

Discussion: Two patients with infantile-onset SCA5 associated with another novel heterozygous SPTBN2 mutation have recently been reported; these SPTBN2 mutations, which may have a significant impact on protein function, were located in the second spectrin. Our findings indicate that SPTBN2 mutations may be associated with infantile-onset cerebellar ataxia accompanied with global developmental delay.

Keywords: Infantile-onset; SPTBN2; Spinocerebellar ataxia; β-III spectrin.

Publication types

  • Case Reports

MeSH terms

  • Child
  • Female
  • Humans
  • Japan
  • Magnetic Resonance Imaging
  • Mutation
  • Mutation, Missense
  • Spectrin / genetics*
  • Spectrin / metabolism
  • Spinocerebellar Ataxias / genetics*
  • Spinocerebellar Ataxias / physiopathology
  • Spinocerebellar Degenerations / genetics*


  • SPTBN2 protein, human
  • Spectrin

Supplementary concepts

  • Infantile onset spinocerebellar ataxia