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Principles of Forensic DNA for Officers of the Court


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illustration of Heteroplasmy
National Institute of Justice (NIJ) (see reuse policy).

Heteroplasmy is defined as the presence of more than one mtDNA type within a single individual. Heteroplasmy was originally believed to be rare among healthy individuals, but scientists now believe that each person has some low- frequency, slightly different mtDNA types mixed in with his or her inherited dominant type. These low-frequency types arise from mtDNA mutations within growing and dividing cells. The two types of heteroplasmy are length heteroplasmy and sequence (or site) heteroplasmy.

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