Subtyping of Y-chromosomal haplogroup E-M78 (E1b1b1a) by SNP assay and its forensic application.

The continual discovery of new single-nucleotide polymorphisms (SNPs) has led to an increased resolution of the Y chromosome phylogeny. Some of these Y-SNPs have shown to be restricted to small geographical regions and therefore may prove useful in the forensic field as tools for the prediction of population of origin of unknown casework samples. Here, we describe a system for the molecular dissection of haplogroup E-M78 (E1b1b1a), consisting of multiplex polymerase chain reaction and minisequencing of M78 and nine population-informative Y-SNPs (M148, M224, V12, V13, V19, V22, V27, V32, V65) in a single reaction. Sensitivity and admixture studies demonstrated that the SNP protocol allows robust genotyping from as little as 50 pg of male DNA, even in the presence of 500-fold amounts of female DNA. In order to evaluate the suitability of E1b1b1a, subhaplogrouping for population-of-origin prediction, the distribution of E-M78 and its derived variants was determined in an Italian population sample (n = 326).