I think it would depend on whether or not your epiphyseal plates in your bones have closed or not. Epiphyseal plates are slices of cartilage in your bones that allow growth. If your plates were still open and you underwent some gene therapy, you could certainly increase your growth. Although, it would be much easier to just take some hormones for the same effect. If your growth plates are closed, I suppose it's possible that some growth may occur, but the effects of growth-inducing genes would more likely create acromegaly.

A present procedure is a treatment with growth hormone, which is produced with recombinant DNA technology: "Growth hormone (GH) is a peptide hormone. It stimulates growth and cell reproduction in humans and other animals. It is a 191-amino acid, single chain polypeptide hormone that is synthesized, stored, and secreted by the somatotroph cells within the lateral wings of the anterior pituitary gland. Somatotrophin refers to the growth hormone produced natively in animals, whereas the term somatropin refers to growth hormone produced by recombinant DNA technology, and is abbreviated "rhGH" in humans. Growth hormone is used clinically to treat children's growth disorders and adult growth hormone deficiency. In recent years, replacement therapies with human growth hormones (HGH) have become popular in the battle against aging. Reported effects include decreased body fat, increased muscle mass, increased bone density, increased energy levels, improved skin tone and texture, and improved immune system function. At this time HGH is still considered a very complex hormone and many of its functions are still unknown." Source and further information: http://en.wikipedia.org/wiki/Growth_hormone Further information: http://en.wikipedia.org/wiki/Recombinant_DNA_technology