Explain in detail about Gene therapy
Gene therapy technology as a whole has yet to be proven and it's meeting a number of stumbling blocks, so may have little impact (low success rate). Should the viral vector invade non-target cells, especially the germ line cells, and integrate its DNA with the individual's DNA, then the possibility of the development of onco-genes in the gametes is increased, which could then be inherited by offspring.
To impact on gene pool would require gene therapy to affect gonads or to alter a zygote early enough in development that the gene was incorporated into all cells.