Survival estimates for patients with Machado–Joseph disease (SCA3)

Authors

  • C Kieling,

    1. Medical Genetics Service, Hospital de Clinicas de Porto Alegre, Porto Alegre, Brazil
    Search for more papers by this author
  • PR Prestes,

    1. Genetics and Molecular Biology Department
    Search for more papers by this author
  • ML Saraiva-Pereira,

    1. Medical Genetics Service, Hospital de Clinicas de Porto Alegre, Porto Alegre, Brazil
    2. Biochemistry Department
    Search for more papers by this author
  • LB Jardim

    Corresponding author
    1. Medical Genetics Service, Hospital de Clinicas de Porto Alegre, Porto Alegre, Brazil
    2. Internal Medicine Department, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil
      Laura Bannach Jardim, Medical Genetics Service, Hospital de Clinicas de Porto Alegre, Rua Ramiro Barcelos, 2350, 90035-903 Porto Alegre, Brazil.
      Tel.: +55 51 2101 8011;
      fax: +55 51 2101 8010;
      e-mail: ljardim@hcpa.ufrgs.br
    Search for more papers by this author

Laura Bannach Jardim, Medical Genetics Service, Hospital de Clinicas de Porto Alegre, Rua Ramiro Barcelos, 2350, 90035-903 Porto Alegre, Brazil.
Tel.: +55 51 2101 8011;
fax: +55 51 2101 8010;
e-mail: ljardim@hcpa.ufrgs.br

Abstract

Machado–Joseph disease (MJD), one of the most prevalent autosomal dominant cerebellar ataxias, is a neurodegenerative disease that starts during adulthood, with patients showing difficulties in gait, later becoming bedridden, and ultimately presenting premature death. There is, however, scarce data quantifying disease impact on patient survival. We investigated the overall survival of a large series of MJD patients and compared it with the survival of their asymptomatic relatives. A total of 412 affected and 413 unaffected individuals were ascertained from a consecutive sample of 82 families with a molecular diagnosis of MJD. Estimated mean survival time was 63.96 years [95% confidence interval (CI), 62.09–65.83] for the affected group and 78.61 years (95% CI, 74.75–82.47) for the unaffected group (p < 0.001). For a subset of 366 patients, mean age at onset was 36.37 years (95% CI, 35.21–37.53) and survival after disease onset was estimated as 21.18 years. Early onset and large CAG length predicted shorter overall survival times. This study presents quantitative data on the impact of MJD on overall survival, a phenomenon that is related to CAG length, age at onset, and year of birth.

Ancillary