Just how close are we to building an airplane?
Now that we have the entire human genome sequenced, were only a few short experiments away from curing genetic diseases like Cystic Fibrosis and Tay-Sachs … right?
With all the hype surrounding the Human Genome Project and its completion at the turn of the century, we must not lose sight of what this incredible accomplishment really means. Eric Landers, one of the leaders of the Human Genome Project, aptly called the project a parts list of the human species in NOVA’s Cracking the Code. So imagine this list, as Landers does, as the parts of a Boeing 777; while it would seem logical to add engines, seats, carpet, doors, and windows to such a list, the metaphorical plane needs to be further deconstructed to be comparable to the human genome.
The list should then consist of ten thousand screws, seven hundred pounds of sheet metal, two square acres of fabric, and eighty-nine pounds of plastic. The genome outlines the most raw and dissected explanation of mankind that has ever existed, but piecing it back together is the true difficulty that modern geneticists are charged with. When the genetic defect that causes Cystic Fibrosis was discovered in 1989, the media went wild, and now that we have the fully sequenced human genome, the defect can be placed within the blueprint of our existence.
While this placement does help inch science closer to treating and possibly curing genetic diseases, it is the equivalent to identifying a screw in an airplane. Looking at a wholly built airplane, one could easily identify a screws location, however as Landers implies, it is difficult to tell how a pile of shrapnel, screws, leather, and plastic will become an airplane. Yes, we now know where the single mutation in the genome that causes Cystic Fibrosis is located, just like a single screw on the wing of a plane, but we still have no idea how to modify the mutation, or what tools would be best.
Yes, there is a screw in the wing, but if we remove it, what effects would it have on flight? Genes function as a result of proteins interpretation of the codes written; however, it is also not as simple as one gene controlling one aspect of a person. There is no single gene for eye color, height, or nose length. Often hundreds of genes impact one physical trait (pleiotropic genes) and one gene can impact hundreds of traits (polygenic traits), all depending on a cell’s environment and modifications of the gene being expressed. It’s the equivalent of removing a screw in the wing and knocking a plane’s radar offline, or adjusting a seat in coach and permanently crippling a passenger in first class. Even the PBS special, Cracking the Code, seemed to set up the interviews of the parents of afflicted children under the guise that this new discovery would quickly lead to a cure for Cystic Fibrosis or Tay-Sachs.
Now I am in no way trying to undervalue the amazing accomplishment that is the Human Genome Project. The data from the massive undertaking has created entirely new and successful methods of disease treatment and has catapulted biomedical innovation into an era unimaginable by scientists twenty years ago. Indeed, we have uncovered the parts list of humanity, but we have only scratched the surface of what that list will tell us. Yes, we are closer than we have ever been to curing Cystic Fibrosis, and we know more about the disease at the molecular level than ever, but the Human Genome Project has also shown that genetics is infinitely more complex than simple Mendelian genetic thought would once suggest.
So where do we go from here? Well, we have the parts, now its time to build the plane. I worry that many people do not know enough about genetics or even biology to understand both the massive discoveries and challenges alike that are going to come from the Human Genome Project. We must begin to ask ourselves how we are going to develop the next generation of scientific minds that can utilize this project to discover the many effects of a single gene, as well as deciding the bioethical issues that will eventually come from such expansive knowledge of the human genome.
My point is this: it is extremely important to keep in mind what this accomplishment is, and what it is not. It is the first major mapping of the human genome that can be used to piece together all we know about genetics. We can use it as a key in mapping out disease and all we currently know about physical traits. However just because we know more, doesn’t mean we know how to change and fix more… at least not yet. It was extremely premature for the 1989 news media to suggest that Cystic Fibrosis treatment would be radically different thanks to the mutation identification, because 20 years later, there is no difference in treatment. However, the Human Genome Project is the first step of unlocking eventual genetic modification for disease treatment and designer babies alike, (something to keep in mind).
TL;DR: were a long way off from building an airplane without any blueprints, but we have every part we need.