DNA from Nails for Genetic Analyses in Large-Scale Epidemiologic Studies

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-12DNAarray (>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 DNAis 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. Impact: 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. (C) 2014 AACR.