mtDNA-Network: a web tool to explore mitochondrial variant profiles in complex diseases

The mitochondrial genome (mtDNA) provides valuable insights into human evolution, population diversity, and disease etiology. Here, we present the mtDNA-network (https://apps.lghm.ufpa.br/mtdna/), an integrative bioinformatics database and tool for the visualization and analysis of mitochondrial variants (single-nucleotide variants and insertions/deletions). The mtDNA-network was upgraded to enable investigation of mtDNA in admixed Brazilian individuals with substantial contributions from uniparental Indigenous and African ancestries. We implement a bioinformatics pipeline to harmonize variant calling across 339 mtDNA samples. The dataset supports general genetic population analysis and variant mapping for complex diseases, including Parkinsons disease (104 cases and 75 controls), leprosy (33 cases and 37 controls), and somatic gastric cancer (40 cases and 50 controls). The mtDNA-network tool features an intuitive interface and analytical dashboards for transitions, transversions, heteroplasmy, and variant-disease networks, and serves as a strategic resource for advancing research in population genetics and precision medicine in underrepresented populations. We reinforce the critical need to expand non-European genomic representation in global databases to promote more equitable genomic diversity studies and clinically relevant discoveries.