Scientific article

Dodecamer repeat expansion in cystatin B gene in progressive myoclonus epilepsy

Published inNature, vol. 386, no. 6627, p. 847-851
Publication date1997

Progressive myoclonus epilepsy of the Unverricht-Lundborg type (EPM1; MIM 254800) is an autosomal recessive disorder with onset between 6 and 13 years followed by variable progression to mental deterioration and cerebellar ataxia. It is a rare disorder but more common in Finland (1 in 20,000) and the western Mediterranean. Two point mutations in the cysteine proteinase inhibitor gene cystatin B (CSTB), proved that this gene is responsible for EPM1 (ref. 3). An extensive search in the CSTB gene revealed mutations accounting only for 14% of the 58 unrelated EPM1 alleles studied. Here we report that the majority of EPM1 alleles contain expansions of a dodecamer (12-mer) repeat located about 70 nucleotides upstream of the transcription start site nearest to the 5' end of the CSTB gene. Normal alleles contain 2 or 3 copies of this repeat whereas mutant alleles contain more than 60 such repeats and have reduced levels of CSTB messenger RNA in blood but not in cell lines. 'Premutation' CSTB alleles with 12-17 repeats show marked instability when transmitted to offspring.

  • Alleles
  • Base Sequence
  • Blotting, Southern
  • Cloning, Molecular
  • Cystatin B
  • Cystatins/ genetics
  • Cysteine Proteinase Inhibitors/ genetics
  • Dna
  • Epilepsies, Myoclonic/ genetics
  • Female
  • Humans
  • Male
  • Molecular Sequence Data
  • Pedigree
  • Polymerase Chain Reaction
  • Repetitive Sequences, Nucleic Acid
Citation (ISO format)
LALIOTI, M. D. et al. Dodecamer repeat expansion in cystatin B gene in progressive myoclonus epilepsy. In: Nature, 1997, vol. 386, n° 6627, p. 847–851. doi: 10.1038/386847a0
Main files (1)
ISSN of the journal0028-0836

Technical informations

Creation07/12/2010 11:58:37 AM
First validation07/12/2010 11:58:37 AM
Update time03/14/2023 3:51:35 PM
Status update03/14/2023 3:51:35 PM
Last indexation02/12/2024 6:53:17 PM
All rights reserved by Archive ouverte UNIGE and the University of GenevaunigeBlack