Reviews of Science for Science Librarians: Direct-to-Consumer DNA Testing for Ancestry as a Complement to Traditional Genealogical Methods

Abstract

ABSTRACT Almost 100 Million Americans have turned to DTC (Direct-to-Consumer) DNA testing kits to identify their forebears and map the biogeographic areas from which they came. Test results for most Americans of European ancestry are highly accurate and very specific as to homelands. They generally confirm carefully constructed traditional document-search-based genealogies, as is the case with East and Southeast Asian immigrants who maintained in-depth family records owing to traditions of filial piety. For a variety of reasons, traditional genealogical approaches and DTC DNA tests of African Americans cannot yet be as highly specific but developments in testing are very promising. DTC DNA testing of Latinx and Indigenous American (Native Americans) remains somewhat problematic in part due to the very high incidence of admixtures of the two groups, which is further complicated by ethical issues over who is, or is not, a genuine member of any particular tribe. Ancestry-oriented DNA kits continue to rely primarily on SNP (Single-Nucleotide-Polymorphisms), Y-chromosome, and mitochondrial DNA tests, with whole-genome tests still primarily reserved for clinical studies, although more and more kit marketing is now providing information with regard to genetic susceptibility to given diseases or medical conditions.