Cloning of the SCA7 gene reveals a highly unstable CAG repeat expansion

  • Nat Genet. 1997 Sep;17(1):65-70. doi: 10.1038/ng0997-65.
G David  1 ,  N Abbas ,  G Stevanin ,  A Dürr ,  G Yvert ,  G Cancel ,  C Weber ,  G Imbert ,  F Saudou ,  E Antoniou ,  H Drabkin ,  R Gemmill ,  P Giunti ,  A Benomar ,  N Wood ,  M Ruberg ,  Y Agid ,  J L Mandel ,  A Brice
Affiliations
  • 1. INSERM U289, Hôpital de la Salpêtrière, Paris, France.
PMID: 9288099 DOI: 10.1038/ng0997-65
Abstract

The gene for spinocerebellar ataxia 7 (SCA7) has been mapped to chromosome 3p12-13. By positional cloning, we have identified a new gene of unknown function containing a CAG repeat that is expanded in SCA7 patients. On mutated alleles, CAG repeat size is highly variable, ranging from 38 to 130 repeats, whereas on normal alleles it ranges from 7 to 17 repeats. Gonadal instability in SCA7 is greater than that observed in any of the seven known neuro-degenerative diseases caused by translated CAG repeat expansions, and is markedly associated with paternal transmissions. SCA7 is the first such disorder in which the degenerative process also affects the retina.