In sum, there is a unique risk posed by SCNT clones that is not posed by other ARTs (artificial reproductive technologies): the potential for aberrant nuclear- mitochondrial interactions. Embryos created via SCNT embryos differ from those created by other ARTs in two ways: they may be heteroplasmic (e.g. contain mtDNA from two sources) and nuclear-encoded mitochondrial DNA transcription and translation factors persist in SCNT, but not IVF, embryos. Given that there is a long list of diseases that are influenced by aberrant mitochondia, any aberrant nuclear-mitochondrial interaction, due to heteroplasmy and/or persistence of mitochondrial transcription and translation factors in the SCNT clones, should raise red flags that deserve more study. The area of mitochondrial diseases is an emerging field and there is a lot of information that is still unknown. Until the FDA understands more about nuclear-mitochondrial cross talk and the impact of heteroplasmy, they should refrain from approving SCNT clones.
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