Ataxia telangiectasia

  • Inheritance
    • AR
  • Mutation
    • Ataxia-telangiectasia gene ATM
    • Regulates cell cycle control and the cellular damage response to double-strand DNA breaks
    • Chromosomal instability
      • Example: increased chromosomal breakage with ionizing radiation, oxidative stress
  • Clinical presentation
    • Triad
      • Severe humoral immunodeficiency (decreased IgA, IgG and IgE)
      • Ataxia due to cerebellar atrophy
      • Capillary malformations (ex. telangiectasia)
    • 1 per 40.000-100.000 births worldwide
    • 25% lifetime risk of malignancy
      • Leukemia/lymphoma
      • Increased sensitivity to ionizing radiation
    • Immunodeficiency: sinopulmonary infections
    • Progressive ataxia
    • Carriers have malignancy risk
    • Oculocutaneous telangiectasia
      • Appear around 3-5 years of age
      • Ocular lesions often striking
      • Skin lesions may be subtel and pinpoint
      • Not present in all patients
    • Non-infectious granulomas (rubella virus in granulomas?)