Related Experiment Video
Updated: Jun 8, 2026

Genotyping Single Nucleotide Polymorphisms in the Mitochondrial Genome by Pyrosequencing
Published on: February 10, 2023
Characterization of mitochondrial DNA sequence heteroplasmy in blood tissue and hair as a function of hair morphology
Katherine A Roberts1, Cassandra Calloway
1School of Criminal Justice and Criminalistics, 1800 Paseo Rancho Castilla, California State University, Los Angeles, Los Angeles, CA 90032, USA. krobert2@exchange.calstatela.edu
Abstract:
This study characterizes mitochondrial DNA (mtDNA) sequence heteroplasmy in blood tissue and hair as a function of hair morphology. Bloodstains (127 individuals) and head hairs (128 individuals) were typed using the mtDNA LINEAR ARRAY™ assay. A total of 1589 hairs were interpreted: 1478 (93%) were homoplasmic and 111 (7%) exhibited heteroplasmy at one or more positions. Seventy-one percent (82/116) of individuals were homoplasmic, whereas 29% (34/116) exhibited heteroplasmy in at least one hair. The results demonstrate intra- and inter-tissue differences in heteroplasmy within individuals. Sequence heteroplasmy among hairs from each individual varied from 0 to 90%; the frequency does not differ significantly with population group, cosmetic treatment, age, gender, medulla morphology, region of the scalp, hair growth phase, or, when comparing living and deceased donors. However, the results support a correlation between heteroplasmy and hair pigmentation; typically, lighter-pigmented hairs exhibit a higher incidence of sequence heteroplasmy compared to darker hairs.
Related Concept Videos
Animal Mitochondrial Genetics
Non-nuclear Inheritance
Genetic Variation
Genes exist in different versions called alleles, which...
Modern Molecular Taxonomy
Evolutionary Relationships through Genome Comparisons

