The TOR1A (DYT1) gene family and its role in early onset torsion dystonia

Genomics. 1999 Dec 15;62(3):377-84. doi: 10.1006/geno.1999.6039.


Most cases of early onset torsion dystonia are caused by a 3-bp deletion (GAG) in the coding region of the TOR1A gene (alias DYT1, DQ2), resulting in loss of a glutamic acid in the carboxy terminal of the encoded protein, torsin A. TOR1A and its homologue TOR1B (alias DQ1) are located adjacent to each other on human chromosome 9q34. Both genes comprise five similar exons; each gene spans a 10-kb region. Mutational analysis of most of the coding region and splice junctions of TOR1A and TOR1B did not reveal additional mutations in typical early onset cases lacking the GAG deletion (N = 17), in dystonic individuals with apparent homozygosity in the 9q34 chromosomal region (N = 5), or in a representative Ashkenazic Jewish individual with late onset dystonia, who shared a common haplotype in the 9q34 region with other late onset individuals in this ethnic group. A database search revealed a family of nine related genes (50-70% similarity) and their orthologues in species including human, mouse, rat, pig, zebrafish, fruitfly, and nematode. At least four of these genes occur in the human genome. Proteins encoded by this gene family share functional domains with the AAA/HSP/Clp-ATPase superfamily of chaperone-like proteins, but appear to represent a distinct evolutionary branch.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adolescent
  • Adult
  • Age of Onset
  • Aged
  • Animals
  • Carrier Proteins / genetics*
  • Child
  • Child, Preschool
  • Chromosome Mapping
  • Chromosomes, Human, Pair 9 / genetics
  • DNA Mutational Analysis
  • Databases, Factual
  • Dystonia Musculorum Deformans / epidemiology
  • Dystonia Musculorum Deformans / genetics*
  • Exons / genetics
  • Founder Effect
  • Genotype
  • Humans
  • Introns / genetics
  • Molecular Chaperones*
  • Multigene Family / genetics*
  • Phylogeny
  • Sequence Homology, Amino Acid
  • Species Specificity


  • Carrier Proteins
  • Dyt1 protein, mouse
  • Molecular Chaperones
  • TOR1A protein, human
  • TOR1B protein, human
  • Tor1a protein, rat