Sequence polymorphism of mitochondrial DNA control region in Japanese.

Sequence polymorphisms of the mitochondrial DNA (mtDNA) control region, hypervariable regions I and II, from 100 unrelated Japanese were determined by PCR amplification and direct sequencing. Sequences of 404 nucleotides for hypervariable region I and 379 nucleotides for region II were obtained. Variable sites (85 and 45) were revealed in region I and region II, respectively, as compared to the reference sequence, and a total of 96 different genetic patterns from both regions I and II were determined. A point mutation heteroplasmy was observed at the ratio of approximately 50:50 from one individual at the sequence position 151 showing a nucleotide transition from C to T. The probability of identity was estimated as 2.3% for region I, 3.9% for region II, and 1.1% combined for both regions. These results suggest that sequence polymorphism of mtDNA control region would be very useful in forensic practice as a marker for individual identification.