Deciphering the cause of Friedreich ataxia.
Friedreich ataxia (FA), the most frequent cause of recessive ataxia, is attributable, in most cases, to a large expansion of an intronic GAA repeat, resulting in decreased expression of the target frataxin gene. This gene encodes a novel mitochondrial protein that has homologues of unknown function in yeast and even in gram-negative bacteria. Yeast deficient in the frataxin homologue accumulate iron in their mitochondria and show increased sensitivity to oxidative stress. This finding suggests that FA patients suffer from a mitochondrial dysfunction that causes free-radical toxicity, reminiscent of the clinically similar ataxia caused by inherited isolated vitamin E deficiency.
Koenig
M
M
Institut de Génétique et Biologie Moléculaire et Cellulaire (IGBMC), INSERM, CNRS, Université Louis Pasteur, Strasbourg, France. mkoenig@igbmc.u-strasbg.fr
Mandel
J L
JL
D000818:Animals; D005621:Friedreich Ataxia / Q000235:genetics* / Q000378:metabolism / Q000503:physiopathology; D006801:Humans; D033862:Iron-Binding Proteins; D017853:Phosphotransferases (Alcohol Group Acceptor) / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D014811:Vitamin E Deficiency / Q000503:physiopathology; D000096923:Frataxin
D033862:Iron-Binding Proteins; D017853:Phosphotransferases (Alcohol Group Acceptor); D000096923:Frataxin