Which practice is recommended when interpreting two-person DNA mixtures to minimize misattribution?

Which practice is recommended when interpreting two-person DNA mixtures to minimize misattribution?

• A. Disregard minor contributor peaks.
• B. Assume all peaks belong to the major contributor.
• C. Always rely solely on peak height without context.
• D. Apply conservative interpretation with consideration of peak heights and possible contributors.

Answer: (D)

Interpreting two-person DNA mixtures requires a careful, conservative approach that weighs evidence across peaks rather than focusing on any single metric. Peak heights alone don’t tell the full story because minor contributors can produce real peaks, and artifacts like stutter, drop-in, or dropout can mimic or obscure true alleles. The best practice is to interpret the data with caution, considering all plausible contributors and whether the observed peak pattern can be explained by a single major contributor or necessitates a second contributor. This mindset helps prevent misattribution by not prematurely assigning peaks to one person and by incorporating locus-to-locus consistency, potential dropout at low-template loci, and allele balance across the loci examined. In contrast, ignoring minor contributor peaks, assuming all peaks come from the major contributor, or relying solely on peak height without context would increase the risk of misinterpreting the mixture.