Evaluation of Kinship Indices for the Identification of Missing Persons

When both parents are able to provide reference DNA samples, the likelihood ratio, or strength of a match, between the parents and their child will be very high for a true match. However, what happens when only one parent is available, or neither parent is available? How effective are other relatives’ DNA profiles at aiding in the identification of an unknown sample? What sort of threshold, if any, should be in place to determine whether an unknown is excluded from being the relative of the reference donor? This study aims to approach an answer these questions by analyzing a database consisted of anonymous samples from the paternity testing division of the University of North Texas Health Science Center DNA Identity Laboratory. The concentration of the study is on whether kinship indices are reliable and consistent in being able to provide information regarding a sibling relationship. Evaluation of the kinship indices of parents and siblings of different families, both within the family and outside of the family, will aid in the determination of whether or not a threshold exists, and what that threshold may be. This information will be invaluable to future cases involving unidentified remains when direct reference samples or parent reference samples are not available.