Differentiating between monozygotic twins in forensics through next generation mtGenome sequencing

Abstract Monozygotic (MZ) twins, considered being genetically identical, cannot be distinguished one from another by forensic short tandem repeat (STR) profiling. The high mutation rate of the mitochondrial DNA (mtDNA) has the potential to become a promising biomarker for the differentiation between MZ twins. With the advent of Next-Generation Sequencing (NGS) approaches, it is now possible to characterize minor differences of mtDNA genomes (mtGenomes) between MZ twins. In this study, we mapped nucleotide differences and heteroplasmies of MZ twins' mtGenomes by NGS technology. Blood samples were taken from 6 pairs of adult MZ twins, and the mtGenomes were sequenced using the Illumina HiSeq 2000 Sequencing System. Point heteroplasmies were observed in five sets of MZ twins and a single nucleotide variant (nt15301) was detected in four sets of MZ twins. Our results give experimental evidence for the hypothesis that variants of mtGenomes could be a perspective biomarker to distinguish MZ twins from each other.