Table of Contents
Heteroplasmy in Mitochondrial DNA: Insights from Pakistani Populations
Last Updated: August 12, 2025
Introduction
What if your cells carried more than one version of your mitochondrial DNA?
This isn’t science fiction — it’s called heteroplasmy, and it can influence everything from disease risk to forensic identification.
In this article, we explore detailed findings from a major genetic study of the Makrani and Kalashi ethnic groups in Pakistan, which revealed unique heteroplasmy patterns with implications for anthropology, medicine, and law enforcement.
Thesis Excerpt & Analysis
“Another source of polymorphism in the mtDNA is the occurrence of different types of mtDNA or population of discrete mtDNA genomes in an individual, which is also called as heteroplasmy… Heteroplasmy is more frequent in the control region than in the coding region of mtDNA” (p. 3).
What is Heteroplasmy?
Heteroplasmy occurs when a single cell contains two or more different mtDNA sequences. This can result from:
- Mutations over a person’s lifetime.
- Inherited variation from the maternal line.
- Mitochondrial bottlenecks during early development.
Findings in the Makrani Population
“Point heteroplasmy was observed at 5 different positions in Makrani accounting for 13% of the individuals. Only one individual presented more than one point heteroplasmy…” (p. ii).
- Lower heteroplasmy frequency than Kalashi.
- Possible cause: Greater genetic diversity diluting repeated mutations.
- Forensic note: Unique enough to aid in individual differentiation.
Findings in the Kalashi Population
“Point heteroplasmy was observed at 6 different positions accounting for 58.56% of the individuals. In this case, three individuals presented more than one point heteroplasmy…” (p. ii).
- Extremely high heteroplasmy rate.
- Suggestive of endogamy (marriage within the same community) and small effective population size.
- Forensic challenge: Higher likelihood of overlapping profiles in unrelated individuals.
Why This Matters in Forensics
“Knowledge of heteroplasmies about the populations when analyzing a sample under question… is crucial in forensic analysis” (p. 9).
- Pros: Can act as a unique genetic “fingerprint” in certain cases.
- Cons: Can complicate match interpretation, especially in small or isolated populations.
Medical and Evolutionary Implications
Heteroplasmy can:
- Influence mitochondrial diseases (e.g., MELAS, Leber’s hereditary optic neuropathy).
- Serve as a marker for aging-related changes in mitochondrial health.
- Provide clues about historical migration patterns.
Conclusion
Heteroplasmy is more than just a genetic oddity — it’s a dynamic feature of our biology with major implications for both forensic science and ancestry research.
In the Makrani and Kalashi populations, it tells two very different stories: one of genetic mixing, and one of long-term isolation.
Disclaimer
Disclaimer: Some sentences have been lightly edited for SEO and readability. For the full, original research, please refer to the complete thesis PDF linked in the section above.
Source & Citations
Thesis Title: Genetic Characterization of Mitochondrial DNA in Makrani and Kalashi Population from Pakistan
Researcher: Muhammad Hassan Siddiqi
Guide (Supervisor): Prof. Dr. Tanveer Akhtar
University: University of the Punjab, Lahore, Pakistan
Year of Compilation: 2014
Excerpt Page Numbers: ii–iii, 3–4, 9, 65–69
Author Bio
Muhammad Hassan Siddiqi is a Pakistani geneticist with a PhD in Zoology from the University of the Punjab. His research focuses on human population genetics, forensic DNA analysis, and mitochondrial DNA variation. He has collaborated internationally in forensic molecular biology and contributed to advancing Pakistan’s genetic databases.
Have you heard of heteroplasmy before? Could it one day replace fingerprints in criminal investigations? Share your opinion in the comments.
Discover more from Professor Of Zoology
Subscribe to get the latest posts sent to your email.