Mitochondrial DNA and Alzheimer's disease: a first case-control study of the Tunisian population

Mol Biol Rep. 2022 Mar;49(3):1687-1700. doi: 10.1007/s11033-021-06978-7. Epub 2021 Dec 1.

Abstract

Background: Alzheimer's disease (AD) is the most common neurodegenerative disorder in humans and presents a major health problem throughout the world. The etiology of AD is complex, and many factors are implicated, including mitochondria. Mitochondrial alteration has been proposed as a possible cause of AD. Therefore, several studies have focused on finding an association between inherited mitochondrial DNA variants and AD onset.

Methods: In this study, we looked, for the first time, for a potential association between mitochondrial haplogroups or polymorphisms and AD in the Tunisian population. We also evaluated the distribution of the major genetic risk factor for AD, the apolipoprotein E epsilon 4 (APOE ε4), in this population. In total, 159 single-nucleotide polymorphisms (SNPs) of mitochondrial DNA haplogroups were genotyped in 254 individuals (58 patients and 196 controls). An additional genotyping of APOE ε4 was performed.

Results: No significant association between mitochondrial haplogroups and AD was found. However, two individual SNPs, A5656G (p = 0.03821, OR = 10.46) and A13759G (p = 0.03719, OR = 10.78), showed a significant association with AD. APOE 4 was confirmed as a risk factor for AD (p = 0.000014).

Conclusion: Our findings may confirm the absence of a relation between mitochondrial haplogroups and AD and support the possible involvement of some inherited variants in the pathogenicity of AD.

Keywords: Alzheimer’s disease (AD); Genetic diversity; Mitochondrial SNPs; Tunisian population; mtDNA haplogroups.

MeSH terms

  • Alleles
  • Alzheimer Disease* / epidemiology
  • Alzheimer Disease* / genetics
  • Apolipoprotein E4 / genetics
  • Apolipoproteins E / genetics
  • Case-Control Studies
  • DNA, Mitochondrial* / genetics
  • Genetic Predisposition to Disease
  • Genotype
  • Humans
  • Mitochondria / genetics
  • Polymorphism, Single Nucleotide / genetics
  • Tunisia / epidemiology

Substances

  • Apolipoprotein E4
  • Apolipoproteins E
  • DNA, Mitochondrial