Forensic analysis of polymorphism and regional stratification of Y-chromosomal microsatellites in Belarus

Abstract

Nine loci defining minimal haplotypes and four other Y-chromosomal short tandem repeats (Y-STRs) DYS437, DYS438, DYS439 and GATA H4.1 were analysed in 414 unrelated males residing in four regions of Belarus. Haplotypes of 328 males were further extended by 7 additional Y-STRs: DYS388, DYS426, DYS448, DYS456, DYS458, DYS460 and DYS635. The 13-locus haplotype diversity was 0.9978 and discrimination capacity was 78.7%, indicating presence of identical haplotypes among unrelated males. Seven additional Y-STRs enabled almost complete discrimination of undifferentiated 13-locus haplotypes, increasing haplotype diversity to 0.9998 and discrimination capacity to 97.9%. Analysis of molecular variance of minimal haplotypes excluded the use of a Y-STR database for Belarusians residing in northeastern Poland as representative for the Belarusian population in forensic practice, and revealed regional stratification within the country. However, four additional markers (DYS437, DYS438, DYS439 and GATA H4.1) were shown to eliminate the observed geographical substructure among Belarusian males. The results imply that in case of minimal and PowerPlex Y haplotypes, a separate frequency database should be used for northern Belarus to estimate Y-STR profile frequencies in forensic casework. In case of Yfiler haplotypes, regional stratification within Belarus may be neglected.