I wouldn't know. Gene expression is very complicated and enviroment dependent. I've read that monozygotic twins sharing same umbilical cord won't have same environment depending on which one gets the cord "first". There are many many subtle diffences (for example inhereted mitochondria might not be evenly distributed, mitochondrial mutations can be inherreted much more by one twin than another). Monozygotic twins won't always have same genome by the time they are born:
https://www.kqed.org/futureofyou/134603/why-identical-twins-dont-always-look-the-same There are also problems of false positives etc. But yeah, frankly, I don't know.
