Identification of CHIP as a novel causative gene for autosomal recessive cerebellar ataxia

PLoS One. 2013 Dec 2;8(12):e81884. doi: 10.1371/journal.pone.0081884. eCollection 2013.

Abstract

Autosomal recessive cerebellar ataxias are a group of neurodegenerative disorders that are characterized by complex clinical and genetic heterogeneity. Although more than 20 disease-causing genes have been identified, many patients are still currently without a molecular diagnosis. In a two-generation autosomal recessive cerebellar ataxia family, we mapped a linkage to a minimal candidate region on chromosome 16p13.3 flanked by single-nucleotide polymorphism markers rs11248850 and rs1218762. By combining the defined linkage region with the whole-exome sequencing results, we identified a homozygous mutation (c.493CT) in CHIP (NM_005861) in this family. Using Sanger sequencing, we also identified two compound heterozygous mutations (c.389AT/c.441GT; c.621C>G/c.707GC) in CHIP gene in two additional kindreds. These mutations co-segregated exactly with the disease in these families and were not observed in 500 control subjects with matched ancestry. CHIP colocalized with NR2A, a subunit of the N-methyl-D-aspartate receptor, in the cerebellum, pons, medulla oblongata, hippocampus and cerebral cortex. Wild-type, but not disease-associated mutant CHIPs promoted the degradation of NR2A, which may underlie the pathogenesis of ataxia. In conclusion, using a combination of whole-exome sequencing and linkage analysis, we identified CHIP, encoding a U-box containing ubiquitin E3 ligase, as a novel causative gene for autosomal recessive cerebellar ataxia.

MeSH terms

  • Adult
  • Amino Acid Sequence
  • Animals
  • Brain / metabolism
  • Cerebellar Ataxia / genetics*
  • Exome / genetics
  • Female
  • Genetic Linkage
  • HEK293 Cells
  • Humans
  • Male
  • Mice
  • Molecular Sequence Data
  • Mutation
  • Pedigree
  • Protein Transport
  • Ubiquitin-Protein Ligases / genetics*
  • Ubiquitin-Protein Ligases / metabolism
  • Young Adult

Substances

  • STUB1 protein, human
  • Ubiquitin-Protein Ligases