In this paper, the authors examine models for the distribution of back stutter ratios, of both one and two repeat units smaller than the parent peak, forward stutter ratios, the two base pair variant DYS19 and the nine base pair variant at DYS385, within the Promega PowerPlex® Y (PPY) multiplex.
The authors have investigated the suitability of models used to predict expected stutter ratios and their variance developed for autosomal STR markers for application of to Y STR markers. Models for expected back stutter, double back stutter, and forward stutter ratios for all loci in the PowerPlex® Y multiplex and the heights of stutter-like artefacts at DYS19 and DYS385 are proposed. The longest uninterrupted stretch of repeats within an allele (LUS), marker and parent allele height was investigated and explanatory variables for stutter ratio and artefact height. The models are intended to be used within an expert system employing a continuous method of DNA interpretation. (Publisher Abstract Provided)