title: DNA from nails for genetic analyses in large-scale epidemiologic studies.
abstract: BACKGROUND
  Nails contain genomic DNA that can be used for genetic analyses, which is attractive for large epidemiologic studies that have collected or are planning to collect nail clippings. Study participants will more readily participate in a study when asked to provide nail samples than when asked to provide a blood sample. In addition, nails are easy and cheap to obtain and store compared with other tissues.
  
  
  METHODS
  We describe our findings on toenail DNA in terms of yield, quality, genotyping a limited set of SNPs with the Sequenom MassARRAY iPLEX platform and high-density genotyping with the Illumina HumanCytoSNP_FFPE-12 DNA array (>262,000 markers). We discuss our findings together with other studies on nail DNA and we compare nails and other frequently used tissue samples as DNA sources.
  
  
  RESULTS
  Although nail DNA is considerably degraded, genotyping a limited set of SNPs with the Sequenom MassARRAY iPLEX platform (average sample call rate, 97.1%) and high-density genotyping with the Illumina HumanCytoSNP_FFPE chip (average sample call rate, 93.8%) were successful.
  
  
  CONCLUSIONS
  Nails are a suitable source of DNA for genotyping in large-scale epidemiologic studies, provided that methods are used that are suitable or optimized for degraded DNA. For genotyping through (next generation) sequencing where DNA degradation is less of an issue, nails may be an even more attractive DNA source, because it surpasses other sources in terms of ease and costs of obtaining and storing the samples.
  
  
  CONCLUSIONS
  It is worthwhile to consider nails as a source of DNA for genotyping in large-scale epidemiologic studies. See all the articles in this CEBP Focus section, "Biomarkers, Biospecimens, and New Technologies in Molecular Epidemiology." Cancer Epidemiol Biomarkers Prev; 23(12); 2703-12. ©2014 AACR.
authors.affiliation: Department of Epidemiology, School for Oncology and Developmental Biology (GROW), Maastricht University, Maastricht, the Netherlands. jgf.hogervorst@maastrichtuniversity.nl.
authors.forename: Janneke G F
authors.initials: JG
authors.lastname: Hogervorst
authors.affiliation: Department of Toxicology, School for Nutrition, Toxicology, and Metabolism (NUTRIM), Maastricht University, Maastricht, the Netherlands.
authors.forename: Roger W L
authors.initials: RW
authors.lastname: Godschalk
authors.affiliation: Department of Epidemiology, School for Oncology and Developmental Biology (GROW), Maastricht University, Maastricht, the Netherlands.
authors.forename: Piet A
authors.initials: PA
authors.lastname: van den Brandt
authors.affiliation: Department of Epidemiology, School for Oncology and Developmental Biology (GROW), Maastricht University, Maastricht, the Netherlands.
authors.forename: Matty P
authors.initials: MP
authors.lastname: Weijenberg
authors.affiliation: Department of Epidemiology, School for Oncology and Developmental Biology (GROW), Maastricht University, Maastricht, the Netherlands.
authors.forename: Bas A J
authors.initials: BA
authors.lastname: Verhage
authors.affiliation: Department of Epidemiology, School for Oncology and Developmental Biology (GROW), Maastricht University, Maastricht, the Netherlands. Department of Toxicology, School for Nutrition, Toxicology, and Metabolism (NUTRIM), Maastricht University, Maastricht, the Netherlands.
authors.forename: Leonie
authors.initials: L
authors.lastname: Jonkers
authors.affiliation: Department of Epidemiology, School for Oncology and Developmental Biology (GROW), Maastricht University, Maastricht, the Netherlands.
authors.forename: Joy
authors.initials: J
authors.lastname: Goessens
authors.affiliation: Department of Epidemiology, School for Oncology and Developmental Biology (GROW), Maastricht University, Maastricht, the Netherlands.
authors.forename: Colinda C J M
authors.initials: CC
authors.lastname: Simons
authors.affiliation: Laboratory for Cytogenetics and Genome Research, Centre for Human Genetics, University Hospital Leuven, KU Leuven, Leuven, Belgium.
authors.forename: Joris R
authors.initials: JR
authors.lastname: Vermeesch
authors.affiliation: Department of Toxicology, School for Nutrition, Toxicology, and Metabolism (NUTRIM), Maastricht University, Maastricht, the Netherlands.
authors.forename: Frederik J
authors.initials: FJ
authors.lastname: van Schooten
authors.affiliation: Department of Epidemiology, School for Oncology and Developmental Biology (GROW), Maastricht University, Maastricht, the Netherlands.
authors.forename: Leo J
authors.initials: LJ
authors.lastname: Schouten
mesh_terms: D000368:Aged; D015331:Cohort Studies; D004247:DNA / Q000235:genetics*; D016021:Epidemiologic Studies; D005260:Female; D005820:Genetic Testing; D005838:Genotype; D006801:Humans; D008297:Male; D008875:Middle Aged; D009262:Nails / Q000166:cytology / Q000378:metabolism*; D011446:Prospective Studies
chemical_list: D004247:DNA