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Measuring Rates of mtDNA Heteroplasmy in Different Population Groups

NCJ Number
Date Published
September 2018
14 pages
The goals of this research were to measure the rate of heteroplasmy across the mtDNA control region (CR) on an individual and per nucleotide basis for people of African, east-Asian, and Latino ancestry, as well as to compare the rates across all population groups, including a study this research team recently completed on Europeans.

Since statistical evaluation of the European dataset has shown possible correlations of heteroplasmy to haplotype, this will be assessed for all population groups. Findings will be used to assist in the refinement of best practices regarding the reporting of mtDNA heteroplasmy, including statistical analysis. The collective findings are expected to assist forensic laboratories as they prepare to report heteroplasmy in casework, which significantly improves the discrimination potential of mtDNA testing. They may also motivate a broader range of forensic laboratories to adopt mtDNA analysis using a massively parallel sequencing (MPS). Currently, 757 buccal and saliva samples have been sequenced. Of these samples, 99 were determined to be of European ancestry, and seven samples were contaminated, for a total of 650 samples of African, Asian, and Latino ancestry. The evaluation of haplotype and assigning haplogroups to population groups indicated that 290 (290/250 or 116 percent) samples belonged to African haplogroups, 247 (247/250 or 98.8 percent to Asian haplogroups, and 113 (113/250 or 45.2 percent) to Latino haplogroups. Of the 650 heliotypes, 83.8 percent (n=545) were unique in the dataset, with a total of 587 different heliotypes (90.3 percent). Of the shared heliotypes, 28 were shared by two individuals, 9 were shared by 3 individuals, 4 were shared by 4 people; and the most common haplotype was shared by six individuals (6/587 or 1.0 percent). 24 bibliographic listings.

Date Published: September 1, 2018