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Interference of nuclear mitochondrial DNA segments in mitochondrial DNA testing resembles biparental transmission of

Renkui Bai1, Hong Cui2, Joseph M Devaney2

  • 1GeneDx Inc, Gaithersburg, MD, USA. rbai@genedx.com.

Genetics in Medicine : Official Journal of the American College of Medical Genetics
|April 13, 2021
PubMed
Abstract

Insights

Recent studies suggest biparental mitochondrial DNA (mtDNA) transmission, but this research indicates paternal mtDNA haplogroups likely result from nuclear DNA segments coamplified during testing, not true inheritance.

Area of Science:

  • Genetics
  • Molecular Biology
  • Human Reproduction

Background:

  • The traditional understanding is that only maternal inheritance of mitochondrial DNA (mtDNA) occurs in humans.
  • Recent reports have challenged this dogma, suggesting biparental mtDNA transmission.

Purpose of the Study:

  • To investigate the authenticity and frequency of biparental mtDNA transmission.
  • To clarify the mechanism behind the observation of two mtDNA haplogroups in individuals.

Main Methods:

  • Retrospective analysis of individuals with two mtDNA haplogroups (2017-2019).
  • Selection of four families for in-depth study.
  • Analysis of heteroplasmy levels in different tissue types and offspring.

Main Results:

  • Identified two mtDNA haplogroups in 104/27,388 (0.38%) unrelated individuals.
  • Observed paternal transmission inconsistent with Mendelian inheritance, with heteroplasmy varying by tissue type.
  • Paternally transmitted mtDNA deletions/duplications showed no disease association.

Conclusions:

  • The observed paternal mtDNA haplogroups are likely artifacts from nuclear mtDNA segments coamplified during testing.
  • Further evaluation of specimen types is needed to determine the clinical significance of these findings.

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