title: High-throughput genotyping of copy number variation in glutathione S-transferases M1 and T1 using real-time PCR in 20,687 individuals.
abstract: OBJECTIVE
  Characteristic for the genes encoding glutathione S-transferase (GST) M1 and GSTT1 is a null allele, suggested to increase susceptibility to chronic diseases. We report an optimized method for the determination of copy number variation (CNV) in GST genes.
  
  
  METHODS
  Real-time multiplex PCR reactions were optimized for quantification of GSTM1 and GSTT1 CNV using the DeltaCt method, a fixed volume of diluted DNA, a total volume of 10 microL, 384-well formats, and single determinations of each sample.
  
  
  RESULTS
  Consistent genotyping was obtained using DNA in a range of 0.41 ng to 100 ng. In a general population sample of 20,687 individuals the genotype frequencies were concordant with other methods used as standards. Throughput was 4600 genotypes per day at a reagent price of 0.5 euros per sample.
  
  
  CONCLUSIONS
  This high-throughput, low cost method accurately determines CNV in the GST genes enabling reliable estimates of disease prediction in large epidemiological samples.
authors.affiliation: Department of Clinical Biochemistry, KB 3011, Section for Molecular Genetics, Rigshospitalet, Copenhagen University Hospital Blegdamsvej 9, DK-2100 Copenhagen Ø, Denmark.
authors.forename: Marianne S
authors.initials: MS
authors.lastname: Nørskov
authors.forename: Ruth
authors.initials: R
authors.lastname: Frikke-Schmidt
authors.forename: Steffen
authors.initials: S
authors.lastname: Loft
authors.forename: Anne
authors.initials: A
authors.lastname: Tybjaerg-Hansen
mesh_terms: D018628:Gene Dosage; D005787:Gene Frequency; D005838:Genotype; D005982:Glutathione Transferase / Q000235:genetics*; D006801:Humans; D008403:Mass Screening; D017720:Molecular Epidemiology / Q000379:methods*; D016133:Polymerase Chain Reaction / Q000379:methods*
chemical_list: D005982:Glutathione Transferase; C413545:glutathione S-transferase T1