Interesting question, I found this

You can’t make a baby with two moms by simply fusing two eggs or adding one egg’s DNA to another’s.  Even though the resulting embryo would have the usual 46 chromosomes, this wouldn’t work.

The reason isn’t some special string of A’s, G’s, T’s or C’s found in dad’s DNA.  No, instead it has to do with chemical marks found on egg and sperm DNA.  This methylation (as the marks are called) makes the DNA from each parent unique, and you need both to make a baby.

What these marks do is affect how at least 80 different genes are used.  In science speak, these genes are imprinted.

As you may remember, we have two copies of each of our genes, one from each biological parent.  The chemical marks shut off either the copy from the egg or sperm, depending on which has the marks present…

If an embryo’s DNA came from two parents of the same sex, then both copies of some of these imprinted genes will be shut off.  And for the rest of these genes, both copies will be turned on.  Embryos simply can’t survive when so many genes are out of whack. In fact, diseases like Angelman syndrome, Prader-Willi syndrome, and Beckwith-Wiedemann syndrome can happen when just one of these genes isn’t passed on properly.

You can read more here if you’re curious