In a baby, their body's DNA will contain a combination of the mother's and father's DNA. In certain situations, there is a mutation in the mother's mitochondrial DNA that causes disease that can occur in the womb or after birth that causes death. In the UK, another baby has been born with a combination of DNA from three different individuals according to a report by Intertesting Engineering.
Mitochondrial donation treatment (MDT) takes 37 genes from donor eggs that do not have mitochondrial mutations. It is then inserted into the embryo from the mother's egg and the father's sperm. With MDT, mitochondrial mutations will be avoided while avoiding death. Although the DNA is a combination of 3 individuals, 98% of the DNA of a born baby is contributed by the real mother and father.
The baby born with a combination of three DNAs has not been identified but is the fifth in medical history. This MDT gene treatment helps couples who often miscarry because the mutation causes the baby to die in the womb or a few years after birth. It may be one of the ways science will try to solve genetic diseases passed from parent to child in the near future.