Related Experiment Video
Updated: Aug 15, 2026

Assessing Differences in Sperm Competitive Ability in Drosophila
Published on: August 22, 2013
[Diversity of paternity index with different allele frequencies]
De-jian Lu1, Qiu-ling Liu, Hui-ling Lu
1Department of Forensic Serology, Zhongshan Medical College of Sun Yat-sen University, Guangzhou, China.
Objective:
To evaluate the diversity of combined paternity index (CPI) of multiple STR loci when different population allele frequencies was used to calculate the paternity index.
Methods:
CPI of 13 CODIS (combined DNA index system) loci for 108 trio cases and 108 duo cases selected randomly were calculated by using five Chinese Han population allele frequencies, respectively.
Results:
The CPI range for trio cases and duo cases were 2077.63-50897711626.46 and 25.12-2998685141, respectively. When different population allele frequencies were applied to the same case, the ratio of maximum CPI and minimum CPI, which was more than 100, for trio cases and duo cases were 20 cases (19.52%) and 13 cases (12.04%), respectively.
Conclusion:
The variation of CPI value of the CODIS loci was obvious with different allele frequencies. To prevent the error causing by uncertain allele frequencies, a conservative CPI value should be calculated in paternity testing.
Related Concept Videos
Hardy-Weinberg Principle
What is Population Genetics?
Genetic Variation
Genes exist in different versions called alleles, which...
Law of Segregation
Law of Independent Assortment
Law of Independent Assortment

