Routine Mitogenome MPS Analysis from 1 and 5 mm of Rootless Human Hair.
Level 5 - mechanism / opinion, no new human data
Laboratory method validation study using human specimens (non-clinical CEBM design analogy)
PubMed 36421819 · doi:10.3390/genes13112144
What was done
Researchers evaluated whole mitochondrial genome (mitogenome) massively parallel sequencing (MPS) on 1 mm and 5 mm rootless hair shaft cuttings from 60 donors, with sample storage ages ranging from less than 5 to 46 years. Hair diameter, length, and medullary structure were evaluated microscopically. Sequencing libraries were prepared using the Promega PowerSeq Whole Mito System prototype kit and sequenced on an Illumina MiSeq platform to evaluate the effects of sample age and physical traits on mtDNA yield, degradation, and sequencing quality.
What was found
Reportable mitogenome sequences were obtained from all tested hairs up to 27 years of age (37 donors). More than 94% of the 74 analyzed hair samples yielded at least 98% of the mitogenome sequence, with an overall minimum sequence coverage of 88%. Haplotypes between 1 mm and 5 mm replicates from the same hairs were fully concordant. Increasing sample age correlated with lower mtDNA yield, higher degradation, and reduced sequence quality, whereas hair diameter and medullary structure had minimal impact.
Why it matters
This study shows that forensic and anthropological investigations can reliably recover full or near-full mitochondrial genomes from rootless hair fragments as short as 1 mm that have been stored for nearly three decades.
Limits
Abstract reporting does not provide quantitative success rates or sequence recovery metrics for hairs aged between 28 and 46 years. The study relied on a prototype sequencing assay and controlled storage samples, which may not reflect the environmental degradation, chemical treatments, or contamination commonly seen in real-world forensic casework.
Cited by
- supports Hair contains high concentrations of mitochondrial DNA, which is what is sequenced in forensic hair analysis.