The Human Genome Project has now completed the first draft of the human genome – all in all, a reasonable task for such an organization. As the genome is explored, patterns found and genes examined, two revolutions in medicine stand to arrive. The first is personalized medicine and the second is genetic engineering.

Everyone has a unique biochemistry – your body functions in a slightly different manner than anyone else’s. The difference is incredibly minute, but also incredibly important. It keeps diseases from spreading like wildfire. A virus that has adapted to live off your roommate may have a hard time making you sick because your body presents a new puzzle.

Genetically engineered crops get wiped out every few years because their biochemistry is too similar. Once a virus or some microscopic organism adapts to feed off one wheat plant, it can devastate the entire crop.

But this idea that everyone is unique can present a problem for medicine. A pharmaceutical company manufacturing a new drug counts on the fact that your body is pretty much the same as everyone else’s. But for some small group of people, this assumption can prove erroneous – sometimes with deadly consequences. That’s why you sometimes hear about a drug that causes liver failure in 5 percent of the population or heart problems in 2 percent.

Suddenly the FDA is forced to pull the drug off the shelves to protect that minority, despite the fact that the same medication may be a godsend for the other 95 or 98 percent of needy patients. But imagine if you could determine in advance which patients would develop liver problems or heart disease. This is the promise of the Human Genome Project. Your genes go a long way toward determining your biochemistry.

Genetic engineering is another field of medicine that will emerge from the Human Genome Project. There are two types of genetic engineering: somatic and germline. The idea of somatic genetic engineering is to correct a genetic disorder by giving someone a copy of a working gene. For instance, trials for cystic fibrosis involve dosing patients with engineered viruses that inject working genes into lung cells to do the work of the faulty genes. Because their method of delivering a gene to a cell is so imprecise, doctors cannot be sure that the body will not react badly to the virus or that genes will not be spliced into the wrong place, causing other genes to malfunction.

Germline engineering stands to be much more effective, but more ethically challenging. Doctors would take the zygote – a fertilized egg, which will become a child – and manipulate its genes. Since all other genes in the child will come from this single cell, the treatment is total and complete. Already, doctors can screen embryos for genetic disorders before using them to make a test tube baby. Some people consider this ethically objectionable, but it is similar in nature to amniocentesis undergone by many parents. For instance, over 90 percent of parents in the U.S. will abort their child if it is found to have Down syndrome.

These are the promises of the HGP. They are also – all of them – problems for the U.S. Neither the FDA nor the healthcare system is set up to handle personalized medicine. These systems are intended for general regulation, not millions of individual cases and medications. Genetic screening already presents a problem. For instance, a genetic test for a cholesterol disorder will also reveal a propensity for Alzheimer’s disease. Of course you might not want to know this. Even if your doctor chooses not to tell you, it will still show up in your medical records, which will be read by your insurance company or perhaps even your employer.

Somatic genetic engineering will present similar problems. Germline engineering will be trickiest of all. Reproductive medicine is currently almost entirely unregulated by the federal government in the United States on the grounds that reproduction is a personal decision for parents to make. But who will decide what kinds of alterations can be made to an embryo? With such procedures uncovered by insurance, will disease-free children be a privilege for the upper middle class?

These are a few of the problems facing our generation. They’re not easy and some of them call into question the very definition of humanity. They are the logical result of a collision course between science, religion and the humanities – and at the same time a place where logic breaks down. But how much of who you are is really the result of genetics? That’s a topic for next time.

Josh Braun is the Daily Nexus science editor.