DESCRIPTION: (Investigators' Abstract) The overall goal of this project is to assess the potential and limitations of the application of genomic sequencing to testing hypotheses of human identity and relationship. Sequencing the human genome will present, very soon, the opportunity to determine with virtual certainty whether independently obtained samples of human material come from the same individual or not, and whether two individuals are biologically related or not. Social and legal applications of this capacity will include identifying deceased victims of accidents, natural disasters, and wars; reuniting separated families; testing claims of identity; and contributing to the solution of crimes. These applications raise the ethical dilemma of balancing the right to know one's identity, the rights of victims of crimes, and the right of privacy. Geneticists can contribute to the discussion of these issues by evaluating the accuracy and limitations of sequencing as a tool for human identification. The use of even perfect sequencing technology appropriately raises ethical concerns; the inaccurate, inappropriate, or ignorant use of this technology invokes truly frightening possibilities. The model system for this project will be direct sequencing of the highly polymorphic control region of the maternally inherited, haploid mtDNA after amplification of target sequences by the polymerase chain reaction. Specifically, the mtDNA control region will be evaluated to determine the most informative portions of the sequence in American populations and the degree to which this variability permits every maternal lineage to be uniquely identified. Standardized techniques for routine sequencing will be developed to circumvent artifacts due to replication errors, contamination, and degradation of DNA. The possibility of obtaining mtDNA sequences from various human tissues, and of determining the true mtDNA sequence regardless of the tissue source of the DNA, will also be assessed. The results of this project should be of use in defining the technical and statistical limits of the genetic approach to human identification. The information and procedures developed could also be incorporated into public policy for the appropriate application of DNA sequencing to human identification.