Should parents modify their child's DNA?

Human DNA modification can drastically change a person's life. Genetic DNA could be used to create a "Designer Baby", where a parent has genetically customized their child's DNA to have certain genes and have none of another.  For example, a baby, was cured of cancer before he was able to walk because doctors were able to genetically mutate his genes.  They had to do this because his father's side of the family has had a long line of cancer and they didn’t want him to be diagnosed too.  They were lucky to be able to catch it earlier.  On the other hand, it could be used to change the appearance of a child, picking and choosing different traits.  It should be legal for a parent to choose whether or not they want to modify their child's genes (with some boundaries).  I believe that it is very beneficial to be able to change the genetics of one's baby, and  It would be okay for a parent to use this technology to prevent a genetic disease/ tumor but unethical for them to use it to change a looks of their child.

First of all, it is the parent’s decision on how they raise their child, whether being hard on them school wise, or letting them decide their future, etc.  In the same way, they should have all the right to mutate their children’s genetics.  If the family is ready to put their child through genetic customizations, then they should.  The same should be held for such actions on the physical appearance of the child (but I think this is completely unethical.  Children should be born the way they were meant to, not the way they are artificially made.  Their appearance is one of the factors what shapes their life, and changes of that may result in a completely different person.).  Restrictions and laws should be made to keep genetic modification safe.  People should never be able to use this new science to create a difficulty for the child in the future, such as causing a cancerous mutation.  A DNA modification pamphlet should be handed out to every single parent/ patient to read, so that they understand fully what the dangers, risks, and benefits of DNA modification really are.