DNA from nails for genetic analyses in large-scale epidemiologic studies

Abstract

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 itsurpasses other sources in terms of ease and costsofobtaining and storing the samples. Impact: It is worthwhile to consider nails as a source of DNA for genotyping 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-12 DNA array (> 262,000 markers). Wediscuss ourfindings together with other studies on nail DNA and we compare nails and other frequently used tissue samples as DNA sources. Results: Although nail DNAisconsiderably degraded, genotyping alimited 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.