Here’s a sciencefitional idea. Gene therapy is the process of inserting new DNA into someone’s cells. This is done with a virus. The virus normally infects a cell by inserting its own DNA into a cell and taking over the production facilities in the cell to make more viruses. By changing the virus and adding the new DNA, the virus infects the cell, but the DNA then becomes part of the cell. Some viruses replicate, but many just fail after the new DNA is in the cell. The new DNA replicates when the cell does and the genes in the new DNA express themselves.
The NY Times article link is about genetic therapy used in sports cheating.
Gene therapy is used as a cure for some cancers, as a legitimate therapy for genetic diseases like sickle cell anemia and cystic fibrosis. It is reasonable to assume that gene therapy might also be used to change developmental characteristics like eye and hair color and body type. It might treat obesity or, as in the times article, create super athletes. I have recently read articles about the genetics of intelligence and gene therapy might be used to raise IQ.
This is the stuff of cyberpunk and “mundane SF”. I think that the more compelling SF stories are near future in that they directly address the important issues of the present by projecting them onto a possible future. I have written a few medical Science fiction stories, and I think there is another one buried somewhere in here.
Here is some good technical information on Gene Therapy.