Whole Mitochondrial Genome Analysis and Forensic DNA Profiling Utility in the Ijaw Population, Bayelsa State

Mitochondrial DNA (mtDNA) is a valuable forensic genetic tool due to its high copy number, maternal inheritance, and persistence in degraded samples. For forensic intelligence databases to be effective, population-specific mtDNA reference data are required. The Ijaw population of Bayelsa State, South South Nigeria, lacks a published forensic mtDNA reference database. This study determined the forensic utility of whole mitochondrial genome sequences in the Ijaw population from Bayelsa State. Two hundred unrelated Ijaw individuals were recruited through community sampling across five clans. Complete mitogenomes were sequenced using a long-range PCR and Sanger sequencing strategy, subsequently validated against Illumina short-read sequencing. Haplogroup assignment was performed using HaploGrep2. Forensic parameters including haplotype diversity, discrimination capacity, and match probability were calculated. High haplotype diversity was documented, consistent with the deep genetic diversity of West African populations. Haplogroup L1, L2, and L3 subclades were most prevalent. The discrimination capacity of complete mitogenome sequencing significantly exceeded that of HVR-I sequencing alone, reinforcing the forensic superiority of complete mitogenome typing. These data provide the first Ijaw-specific forensic mitogenome reference database and support admissibility of mtDNA evidence in Nigerian courts. Keywords: mitochondrial genome, forensic genetics, Ijaw population, Bayelsa State, haplotype diversity