PUBLICATION

Recessive Mutations in the α3 (VI) Collagen Gene COL6A3 Cause Early-Onset Isolated Dystonia

Authors
Zech, M., Lam, D.D., Francescatto, L., Schormair, B., Salminen, A.V., Jochim, A., Wieland, T., Lichtner, P., Peters, A., Gieger, C., Lochmüller, H., Strom, T.M., Haslinger, B., Katsanis, N., Winkelmann, J.
ID
ZDB-PUB-150526-6
Date
2015
Source
American journal of human genetics   96(6): 883-93 (Journal)
Registered Authors
Francescatto, Ludmila, Katsanis, Nicholas
Keywords
none
MeSH Terms
  • Animals
  • Base Sequence
  • Collagen Type VI/genetics*
  • Computational Biology
  • DNA Mutational Analysis
  • Dystonic Disorders/genetics*
  • Dystonic Disorders/pathology*
  • Exome/genetics
  • Genes, Recessive
  • Genetic Testing
  • Genetic Variation*
  • In Situ Hybridization
  • Magnetic Resonance Imaging
  • Mice
  • Molecular Sequence Data
  • Muscle, Skeletal
  • Mutation/genetics
  • Pedigree
  • Zebrafish/genetics
PubMed
26004199 Full text @ Am. J. Hum. Genet.
Abstract
Isolated dystonia is a disorder characterized by involuntary twisting postures arising from sustained muscle contractions. Although autosomal-dominant mutations in TOR1A, THAP1, and GNAL have been found in some cases, the molecular mechanisms underlying isolated dystonia are largely unknown. In addition, although emphasis has been placed on dominant isolated dystonia, the disorder is also transmitted as a recessive trait, for which no mutations have been defined. Using whole-exome sequencing in a recessive isolated dystonia-affected kindred, we identified disease-segregating compound heterozygous mutations in COL6A3, a collagen VI gene associated previously with muscular dystrophy. Genetic screening of a further 367 isolated dystonia subjects revealed two additional recessive pedigrees harboring compound heterozygous mutations in COL6A3. Strikingly, all affected individuals had at least one pathogenic allele in exon 41, including an exon-skipping mutation that induced an in-frame deletion. We tested the hypothesis that disruption of this exon is pathognomonic for isolated dystonia by inducing a series of in-frame deletions in zebrafish embryos. Consistent with our human genetics data, suppression of the exon 41 ortholog caused deficits in axonal outgrowth, whereas suppression of other exons phenocopied collagen deposition mutants. All recessive mutation carriers demonstrated early-onset segmental isolated dystonia without muscular disease. Finally, we show that Col6a3 is expressed in neurons, with relevant mRNA levels detectable throughout the adult mouse brain. Taken together, our data indicate that loss-of-function mutations affecting a specific region of COL6A3 cause recessive isolated dystonia with underlying neurodevelopmental deficits and highlight the brain extracellular matrix as a contributor to dystonia pathogenesis.
Genes / Markers
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Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Antibodies
Orthology
Engineered Foreign Genes
Mapping