I'll leave my opinion regarding DNA as an aspect of personhood at this...
DNA may be used to distinguish between entities that we already identify as humans, but it says absolutely nothing about personhood. The most that can be said is that an entity must have human DNA to be a person. This is not equivalent to all things possessing human DNA are persons. Using DNA as a defining characteristic, regardless of degree, is misplaced. We have already limited the discussion to humans. The existence of a myriad of things containing human DNA that cannot reasonably said to possess the characteristics of personhood also makes the notion ridiculous.
DNA may be used to distinguish between entities that we already identify as humans, but it says absolutely nothing about personhood. The most that can be said is that an entity must have human DNA to be a person. This is not equivalent to all things possessing human DNA are persons. Using DNA as a defining characteristic, regardless of degree, is misplaced. We have already limited the discussion to humans. The existence of a myriad of things containing human DNA that cannot reasonably said to possess the characteristics of personhood also makes the notion ridiculous.