How do you mean? A person can be genetically predisposed to be tall, but grow up to be short due to environmental circumstances (eg lack of nutrition during childhood)
Edit: I figured this would go without saying, but maybe not: this idea, I think logically, extends to things like dopamine thresholds in the brain, and other, erhm, neurotransmittal (word?) aspects of the body. Really, all aspects of the body start with genetic predisposition and then do or do not undergo changes corresponding with the environment. To be completely clear, I am not a scientist. If the science doesnt support this, then Id happily stand corrected