What are current social and ethical concerns regarding gene therapy?

As we learn more about the human genome, or our genetic make-up, we learn more about ways we can solve problems such as genetic disorders, irreparable damage to organs and tissue, and other issues. As with many new fields of science, genetic studies have been met with a fair amount of resistance on moral and ethical grounds. 

For example, when someone has a stroke, a section of their brain dies away. People who have had a stroke have some function loss ranging anywhere from lower muscle movement to large-scale paralysis. Gene therapy could one day be used to fix this by inserting blank stem cells into the damaged tissue and "programming" the blank stem cells with the patient's DNA so he or she can begin to repair brain tissue. Similar illnesses such as heart attacks or organ failure could also be replaced this way. By starting with some blank stem cells, we could grow organs and tissue for patients with their exact DNA, alleviating the need to match blood types or have to take immuno-suppressors to keep the body from attacking the organ. 

The problem keeping us from advancing this technology is where to find the stem cells needed. Stem cells are primarily found in the fetal tissue of infants; adult humans have very few and they are only designed to become different red or white blood cells. The best sources for fetal tissue would be babies who died in the womb or were aborted. This opens huge moral implications as scientists may (a BIG may) be willing to use the tissue for studies, but very few places would be comfortable selling or giving them the tissue in the first place. Planned Parenthood, the US-based sexual-health organization, performs abortions and is restricted from selling the aborted tissue for fear of it becoming some sort of a business leading to an increased demand of fetal tissue. 

There are other arguments for and against gene therapy. An age-old argument is that messing with a human's DNA is always wrong, or we might have implications down the road we don't know about. This last concern is very real, as we are still learning more about human DNA every day in the Human Genome Project and are unsure what every gene and section does. We could attempt to change a growing infant's DNA to prevent Down's Syndrome or Muscular Dystrophy and create issues much worse than the disorder we were attempting to solve. All real fears aside, one day we will know enough to nearly perfect the process and be able to fix most genetic disorders pre-conception so the baby never has to undergo any sort of genetic therapy, but we will never know if we cannot get past the barriers we have set to attempt to study the process. We may have ethical and moral obligations, but unless we can find a way to appease everyone the science will never advance beyond the dreaming stage, and genetic disorders that could have been very treatable early on will continue to wreak havoc in people's lives.