Variation in Mitochondrial DNA Heteroplasmy from Blood, Buccal, and Hair Samples

Mitochondrial DNA (mtDNA) sequence variation has important forensic implications. This research assesses five subjects for variation in point heteroplasmy (PHP) using blood, buccal, and head hair from five scalp sites. Five hairs from each site (25 total hairs) were sequenced for mtDNA using the Ion Chef and S5 technologies. Three hairs were used to study PHP variation along the hair shaft. Variance in hair PHP was more similar to blood (R2 = 0.3411) than buccal (R2 = 0.3059). Given sufficient signal, PHP was detected in all subjects, but was not concordant within or across all scalp sites. Along hair shafts, PHP was present in one distal hair portion. Future research is needed to elucidate PHP's impact on hair sample interpretation.