title: Detection of IL28B SNP DNA from buccal epithelial cells, small amounts of serum, and dried blood spots.
abstract: OBJECTIVE
  Point mutations in the coding region of the interleukin 28 gene (rs12979860) have recently been identified for predicting the outcome of treatment of hepatitis C virus infection. This polymorphism detection was based on whole blood DNA extraction. Alternatively, DNA for genetic diagnosis has been derived from buccal epithelial cells (BEC), dried blood spots (DBS), and genomic DNA from serum. The aim of the study was to investigate the reliability and accuracy of alternative routes of testing for single nucleotide polymorphism allele rs12979860CC.
  
  
  METHODS
  Blood, plasma, and sera samples from 200 patients were extracted (400 µL). Buccal smears were tested using an FTA card. To simulate postal delay, we tested the influence of storage at ambient temperature on the different sources of DNA at five time points (baseline, 48 h, 6 days, 9 days, and 12 days).
  
  
  RESULTS
  There was 100% concordance between blood, plasma, sera, and BEC, validating the use of DNA extracted from BEC collected on cytology brushes for genetic testing. Genetic variations in HPTR1 gene were detected using smear technique in blood smear (3620 copies) as well as in buccal smears (5870 copies). These results are similar to those for whole blood diluted at 1/10. A minimum of 0.04 µL, 4 µL, and 40 µL was necessary to obtain exploitable results respectively for whole blood, sera, and plasma. No significant variation between each time point was observed for the different sources of DNA. IL28B SNPs analysis at these different time points showed the same results using the four sources of DNA.
  
  
  CONCLUSIONS
  We demonstrated that genomic DNA extraction from buccal cells, small amounts of serum, and dried blood spots is an alternative to DNA extracted from peripheral blood cells and is helpful in retrospective and prospective studies for multiple genetic markers, specifically in hard-to-reach individuals.
authors.affiliation: Laboratoire Alphabio, Hôpital Ambroise Paré, Marseille, France. philippe.halfon@alphabio.fr
authors.forename: Philippe
authors.initials: P
authors.lastname: Halfon
authors.forename: Denis
authors.initials: D
authors.lastname: Ouzan
authors.forename: Hacène
authors.initials: H
authors.lastname: Khiri
authors.forename: Guillaume
authors.initials: G
authors.lastname: Pénaranda
authors.forename: Paul
authors.initials: P
authors.lastname: Castellani
authors.forename: Valerie
authors.initials: V
authors.lastname: Oulès
authors.forename: Asma
authors.initials: A
authors.lastname: Kahloun
authors.forename: Nolwenn
authors.initials: N
authors.lastname: Amrani
authors.forename: Lise
authors.initials: L
authors.lastname: Fanteria
authors.forename: Agnès
authors.initials: A
authors.lastname: Martineau
authors.forename: Lou
authors.initials: L
authors.lastname: Naldi
authors.forename: Marc
authors.initials: M
authors.lastname: Bourlière
mesh_terms: D000368:Aged; D004247:DNA / Q000097:blood*; D019698:Hepatitis C, Chronic / Q000175:diagnosis / Q000235:genetics; D006801:Humans; D007372:Interferons; D007378:Interleukins / Q000235:genetics*; D008875:Middle Aged; D009061:Mouth Mucosa / Q000166:cytology / Q000378:metabolism*; D020641:Polymorphism, Single Nucleotide; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013997:Time Factors; D000095022:Interferon Lambda
chemical_list: D004247:DNA; D007372:Interferons; D007378:Interleukins; C000624353:interferon-lambda, human; D000095022:Interferon Lambda