[Diversity of paternity index with different allele frequencies].
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.


CONCLUSIONS
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.
Lu
De-jian
DJ
Department of Forensic Serology, Zhongshan Medical College of Sun Yat-sen University, Guangzhou, China.
Liu
Qiu-ling
QL
Lu
Hui-ling
HL
D000483:Alleles; D002681:China; D016172:DNA Fingerprinting; D005554:Forensic Medicine; D005787:Gene Frequency; D005828:Genetics, Population; D006801:Humans; D010334:Paternity; D020080:Tandem Repeat Sequences / Q000235:genetics*