The babies were born to women who had problems conceiving. Extra genes from a female donor were inserted into their eggs before they were fertilised in an attempt to enable them to conceive.
Genetic fingerprint tests on two one-year- old children confirm that they have inherited DNA from three adults --two women and one man.
The fact that the children have inherited the extra genes and incorporated them into their 'germline' means that they will, in turn, be able to pass them on to their own offspring.
We officially have polluted the stream. It really is unknown how long the butterfly effect will take genetically for mutations to show up in even a single percentage of the population. Still it will eventually occur where these children if they do indeed reach reproductive age and reproduce viable feti. The changes in our DNA and RNA to produce the range of variations in humanity and other carbon based life forms are absolutely minute. In this case large portions of the subjects genome has been altered.
No one can predict what this will do to humanity if they do reproduce. But to assume it will do nothing is foolishness at best.