Generally speaking, yes. Having the genome of a person could be viewed roughly as having the code to a computer program. What this doesn't allow you to do is predict a future state of the program when it is actually running. It is computationally intractable to predict the personality and intelligence of some future state given only the starting state. At best the genome allows you to make probabilistic guesses as to the bulk properties of a person in the abstract, but tells you exactly dick about the characteristics of an instance at some specific point in time. A basic limitation per computational theory.
The State doesn't rely on perfect DNA. It nurtures and monitors, and adjusts as well, and keeps doing this all the way to the end.