| This study investigated rare, genetic anomalies known as variant alleles, and their role in resolving paternity disputes. Paternity analysis typically involves the comparison of DNA profiles from a mother, child and alleged father, and conclusions are drawn based on the genetic evidence. In the past, most variant alleles could not be utilized in these analyses, leading to weaker genetic support for the conclusions. A total of 32,671 DNA profiles were examined for variant alleles. A selection of affected samples were quantified, amplified and subjected to gel electrophoresis to confirm the presence of variant alleles. A total of 85 variant alleles at 12 of the 13 CODIS loci were confirmed in 757 samples. The affected samples were sorted by racial group in order to calculate allele frequencies. Twenty-eight of the variant alleles were observed in 5 or more samples, regardless of racial group, and were added to the Orchid GeneScreen allele frequency database for use in paternity calculations. Paternity analyses were performed on two cases to demonstrate that the use of variant allele data greatly increases the strength of the genetic evidence, providing further support for the paternity conclusions. It is expected that the regular use of these alleles may lead to a reduction in laboratory expenditures, minimize the need for additional testing and decrease the turn-around time for reporting results. In addition, 50 of the variant alleles were listed on the STRBase website as a reference for others in the paternity and forensic science communities. |
