Choosing relatives for DNA identification of missing persons

Area of Science:

• Forensic Genetics
• Human Identification
• Population Genetics

Background:

• DNA analysis is crucial for missing person identification.
• Kinship analysis using indirect relatives is employed when direct references are unavailable.
• Optimizing reference relative selection is vital due to the cost of genetic typing.

Purpose of the Study:

• To rank the informational content of various reference relative combinations for missing person identification.
• To evaluate the efficiency of different genetic markers in kinship analysis.
• To guide strategic selection of relatives for DNA typing in forensic investigations.

Main Methods:

• Simulation of 37 common reference scenarios using pedigrees.
• Analysis of 13 CODIS Short Tandem Repeat (STR) loci.
• Evaluation of likelihood ratios based on genetic marker data.

Main Results:

• First-order relatives (parents, full siblings) provide the highest information content for identification.
• Full siblings are also highly informative genetic references.
• Combinations of relatives with less genetic dependence yield higher average likelihood ratios.
• Autosomal markers alone may be insufficient for distant relatives; Y-chromosome and mitochondrial DNA markers enhance identification or exclusion.

Conclusions:

• Strategic selection of first-order relatives maximizes identification accuracy in missing person cases.
• Utilizing Y-chromosome and mitochondrial DNA markers can improve the power of kinship analysis, especially for complex pedigrees or distant relationships.
• The study provides a framework for optimizing DNA reference strategies in forensic identification.