Subject: Is it possible? Has an experiment like/similar to this ever been done?

This is my idea: Since our society now a day is capable of 
taking out a feterlize egg, analyze it and make a
probable guess on what the traits of the child will have. I was 
thinking of actually locating a deffected gene (a disease), 
take it out and actually replace it with a good gene so that 
that type of deffected gene(s) won't be pass on to the next 
genration. However, i will NOT be doing an actual experience 
with human  gene but a bacteria one in subtitution, and then 
from that result come up with a theory. Where can i get 
information about such topics or anything related to it? Pls 
inform me with any information that you know about this topic 
or anything related to it. Thank you for your time. 

Re: Is it possible? Has an experiment like/similar to this ever been done?