Modelling PowerPlex® Y stutter and artefacts.

We have investigated the suitability of models used to predict expected stutter ratios and their variance developed for autosomal STR markers for application 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 as 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.