Ataxia-oculomotor apraxia 2 patients show no increased sensitivity to ionizing radiation.
Mutations in senataxin have been described recently in 24 cases of French-Canadian descent with ataxia-oculomotor apraxia 2. This recessive ataxia is associated with an elevation in alpha-fetoprotein as in ataxia-telangiectasia. Because ataxia-telangiectasia cells are highly radiosensitive, we used a colony survival assay to measure the radiosensitivity of lymphoblastoid cell lines derived from five French-Canadian patients with ataxia-oculomotor apraxia 2. Two were homozygous for the common French-Canadian L1976R SETX missense mutation; the three others were compound heterozygotes for the common mutation and three different missense mutations. Overall, lymphoblastoid cell lines derived from these cases did not show significant variation from a normal response to 1 Gray of ionizing radiation but the two patients who were homozygous for the common L1976R mutation fell in the intermediate or non-diagnostic range.
Nahas
S A
SA
UCLA School of Medicine, Department of Pathology & Laboratory Medicine, Macdonald Research Laboratories, Los Angeles, CA, USA.
Duquette
A
A
Roddier
K
K
Gatti
R A
RA
Brais
B
B
D000293:Adolescent; D001072:Apraxias / Q000175:diagnosis* / Q000235:genetics / Q000276:immunology; D001259:Ataxia / Q000175:diagnosis* / Q000235:genetics / Q000276:immunology; D002460:Cell Line; D002648:Child; D003114:Colony-Forming Units Assay / Q000379:methods; D004265:DNA Helicases; D004252:DNA Mutational Analysis; D020022:Genetic Predisposition to Disease / Q000235:genetics; D006801:Humans; D008214:Lymphocytes / Q000502:physiology / Q000528:radiation effects; D064251:Multifunctional Enzymes; D009154:Mutation / Q000235:genetics; D009369:Neoplasms / Q000175:diagnosis / Q000235:genetics; D015835:Ocular Motility Disorders / Q000175:diagnosis* / Q000235:genetics / Q000276:immunology; D011379:Prognosis; D011792:Quebec / Q000208:ethnology; D020365:RNA Helicases / Q000235:genetics; D011839:Radiation, Ionizing; D000509:alpha-Fetoproteins / Q000235:genetics
D064251:Multifunctional Enzymes; D000509:alpha-Fetoproteins; C484368:SETX protein, human; D004265:DNA Helicases; D020365:RNA Helicases