“Do not deceive yourselves. If any of you think you are wise by the standards of this age, you should become ‘fools’ so that you may become wise.” – 1 Corinthians 3:18
When the Lord says, "Before I formed you in the womb I knew you", who is any "scientist" to defy Him?
We are already doing gene therapy in utero, and it’s been successful; and science will some day be able to to treat diseases this way after birth.
If you would deny your suffering child that therapy, because you believe that God made the child’s DNA that way and it should stay that way no matter the suffering -
Then in my opinion you would not be ‘religious’; you would be a religious fanatic and guilty of leaving your child to suffer.