title: [Genetic diagnostic methods in ataxia-telangiectasia (Louis-Bar syndrome)].
abstract: OBJECTIVE
  To introduce important genetic diagnostic methods for diagnosis of ataxia telangiectasia.
  
  
  METHODS
  Methods comprised: standard neuropsychiatric and ophthalmologic clinical investigations, analysis of karyograms obtained from cultured lymphocytes, and electronic measurements of lymphocyte nuclei for establishing phases of the cell cycle in radiated and non-radiated lymphocytes that were recovered from a patient.
  
  
  RESULTS
  Cerebellar atrophy in MRT was associated with typical neuroophthalmological symptoms. Structural chromosomal abnormalities with deletion or translocation was found. The cell cycle study showed a characteristic high sensitivity on radiation; particularly high reduction of active cells after radiation was observed in the G1 and S phases. The defective G1/S and S checkpoints were established. The G2/GF ratio was more than threefold higher compared to that of the control group. A very high alpha-fetoprotein level was also noticed.
  
  
  CONCLUSIONS
  A clinical diagnosis of ataxia-telangiectasia should be confirmed through genetic methods.
authors.affiliation: Kliniki Okulistycznej w Centrum Medycznym im. R. Virchowa w Salzgitter.
authors.forename: Heinrich
authors.initials: H
authors.lastname: Holak
authors.forename: Sophie
authors.initials: S
authors.lastname: Holak
authors.forename: Nikolai
authors.initials: N
authors.lastname: Holak
authors.forename: Ulrich
authors.initials: U
authors.lastname: Loel
mesh_terms: D000328:Adult; D001260:Ataxia Telangiectasia / Q000175:diagnosis* / Q000235:genetics* / Q000473:pathology; D064007:Ataxia Telangiectasia Mutated Proteins; D015415:Biomarkers / Q000378:metabolism; D002453:Cell Cycle; D018797:Cell Cycle Proteins / Q000378:metabolism; D002869:Chromosome Aberrations; D025063:Chromosome Disorders / Q000175:diagnosis* / Q000235:genetics; D002883:Chromosomes, Human, Pair 14; D002897:Chromosomes, Human, Pair 7; D004268:DNA-Binding Proteins / Q000378:metabolism; D005819:Genetic Markers; D006801:Humans; D007621:Karyotyping / Q000379:methods; D008214:Lymphocytes / Q000166:cytology*; D008297:Male; D009460:Neurologic Examination; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D025521:Tumor Suppressor Proteins / Q000378:metabolism; D000509:alpha-Fetoproteins / Q000378:metabolism
chemical_list: D015415:Biomarkers; D018797:Cell Cycle Proteins; D004268:DNA-Binding Proteins; D005819:Genetic Markers; D025521:Tumor Suppressor Proteins; D000509:alpha-Fetoproteins; C576324:ATM protein, human; D064007:Ataxia Telangiectasia Mutated Proteins; D017346:Protein Serine-Threonine Kinases