Your Genetic Heritage: DNA Testing

By Nancy Gadzuk

Jennifer Daugherty, Special Collections Librarian for the New Hanover County Public Library, spoke on Your Genetic Heritage at the July 17, 2017 meeting of the History Center.

Jennifer explained that while some DNA testing can determine paternal lineage (y-DNA testing) and some maternal lineage (mitochondrial DNA testing), most DNA testing is autosomal. Autosomes are the chromosomes that do not determine sex, but determine the rest of a person’s genetic make-up.

She talked about three genealogical testing companies she has used. The companies – AncestryDNA, 23andMe, and Family Tree DNA – all are creating databases using the DNA of people who purchase their companies’ DNA tests. These people may self-identify with an ethnicity based on their personal history.

This identification by ethnicity, while not strictly DNA-based, becomes part of a larger geographical and historical component of the overall genealogical profile.

The more people these companies can attract to DNA testing, the larger their databases will become. This leads to providing, among other things, more robust family trees for participating clients. AncestryDNA has the largest database of client DNA, with more than 1 million genetic samples.

Both AncestryDNA and 23andMe sell their clients’ data to pharmaceutical and biotechnology companies. Family Tree DNA has said it will not sell client data.

Jennifer listed briefly some of the characteristics of the three companies she discussed as a summary to her presentation.