Familial writer's cramp: a clinical clue for inherited coenzyme Q10 deficiency

Neurogenetics. 2021 Mar;22(1):81-86. doi: 10.1007/s10048-020-00624-3. Epub 2020 Aug 24.


The spectrum of coenzyme Q10 (CoQ10) deficiency syndromes comprises a variety of disorders, including a form of autosomal recessive cerebellar ataxia (ARCA2) caused by mutations in the AarF domain-containing kinase 3 gene (ADCK3). Due to the potential response to CoQ10 supplementation, a timely diagnosis is crucial. Herein, we describe two siblings with a novel homozygous ADCK3 variant and an unusual presentation consisting of isolated writer's cramp with adult-onset. Cerebellar ataxia developed later in the disease course and remained stable during the follow-up. This report highlights that ARCA2 should be considered in the differential diagnosis of familial writer's cramp.

Keywords: Ataxia; Coenzyme Q10; Dystonia; Magnetic resonance spectroscopy; Mitochondrial disease; Ubiquinone.

Publication types

  • Case Reports
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Ataxia / genetics
  • Cerebellar Ataxia / diagnosis
  • Cerebellar Ataxia / genetics
  • Dystonic Disorders / diagnosis
  • Dystonic Disorders / genetics*
  • Female
  • Homozygote
  • Humans
  • Mitochondrial Proteins / genetics
  • Mutation / genetics*
  • Ubiquinone / analogs & derivatives*
  • Ubiquinone / deficiency
  • Ubiquinone / genetics
  • Ubiquinone / metabolism


  • Mitochondrial Proteins
  • Ubiquinone
  • coenzyme Q10
  • Ubiquinone Q2