on Estimating the Rarity of Y STR Haplotypes

ABSTRACT: Three sampled populations of unrelated males—African American, Caucasian, and Hispanic, all from Texas—were typed for 16 Y short tandem repeat (STR) markers using the AmpFlSTR YfilerTM kit. These samples also were typed previously for the 13 core CODIS autosomal STR loci. Most of the 16 marker haplotypes (2478 out of 2551 distinct haplotypes) were observed only once in the data sets. Haplotype diversities were 99.88%, 99.89%, and 99.87 % for the African American, Caucasian, and Hispanic sample populations, respectively. FST values were very small when a haplotype comprised 10–16 markers. This suggests that inclusion of substructure correction is not required. However, haplotypes consisting of fewer loci may require the inclusion of FST corrections. The testing of independence of autosomal and Y STRs supports the proposition that the frequencies of autosomal and Y STR profiles can be combined using the product rule