sbg, you seem to want 1 century persons to understand 21st century medicine and science.
Paul tells us this:
1 Corinthians 15:21-23,45-49
So you see, just as death came into the world through a man, now the resurrection from the dead has begun through another man. Just as everyone dies because we all belong to Adam, everyone who belongs to Christ will be given new life. But there is an order to this resurrection: Christ was raised as the first of the harvest; then all who belong to Christ will be raised when he comes back.
The Scriptures tell us, “The first man, Adam, became a living person.” But the last Adam—that is, Christ—is a life-giving Spirit. What comes first is the natural body, then the spiritual body comes later. Adam, the first man, was made from the dust of the earth, while Christ, the second man, came from heaven. Earthly people are like the earthly man, and heavenly people are like the heavenly man. Just as we are now like the earthly man, we will someday be like the heavenly man.
We see that Jesus is fully God and fully human. What we will not know is whether God used Mary's genome or whether God did what he did with the first Adam...created a human.
Since Jesus is identified as the second Adam, a human created with no sin nature, but capable of being tempted in all things like the 1st Adam, I have no problem with God not using Mary's genome, but instead creating a new genome for His Son to have. Either way, it takes nothing away from Jesus being fully God and fully man.