How successful is commercial DNA testing in resolving British & Irish cases of unknown parentage?

This study is the first to characterise the type of people trying to resolve unknown parentage cases in the UK and Ireland, and how successful their efforts are, using commercial DTC (direct-to-consumer) DNA tests. A survey was conducted of individuals born in the UK or Ireland, or with a biological parent from the UK or Ireland, who had used genetic genealogy as a part of their search for one or both biological parents. Success rates were high with DNA assisting the identification of a birth parent in 48-55% of cases. In an additional 20-21% of cases, DNA identified grandparents or more distant ancestors. The majority of those identifying a biological parent did so within 6 months of receiving their DNA results (39-55% of cases), and within 2 years, 78-87%% had identified a biological parent. When they first got their results, 40% had very close matches (half-first cousin or closer), an additional 33% had close matches in the second cousin range, and the remaining 27% had more distant matches. The survey also attempted to assess the likelihood of success of the combined use of GEDmatch and FTDNA in IGG (investigative genetic genealogy) cases in Britain and Ireland and found that potentially IGG-suitable matches were present in about 60% of cases. These results complement those of earlier studies and have important implications for social policy in the UK and Ireland. Keywords – DNA; genetic genealogy; unknown parentage; adoptee; foundling; unknown father; donor-conceived; survey