Last time, I wrote about how gene therapy is being used to fix certain kinds of errors in DNA, and so cure or significantly reduce certain kinds of cancers. I asked whether you would accept such a treatment for yourself.
It’s one thing to accept the risks that are associated with these still new and experimental treatments, but would you make that decision for a sick child—one of your children?
I didn’t make a point of it last time, but two of the diseases for which this kind of gene therapy is now available, B-cell acute lymphoblastic leukemia (ALL) and junctional epidermolysis bullosa (“butterfly skin”), are both childhood diseases. The children who received these treatments either were not responding to existing treatments anymore or there were no other treatments available. These kids’ parents were left with the choice of trying these experimental approaches or watching their children die. I think most parents wouldn’t consider that much of a choice.
The FDA has also approved a gene therapy for adults with non-Hodgkin lymphoma, another kind of cancer.
But what if the situation was not so dire? Doctors know, for example, that sickle cell disease is caused by a “single nucleotide polymorphism,” in plain English, an error in just one amino acid in one gene in a person’s DNA. The sickle cell mutation, which has to be inherited from both parents, is not usually fatal in children, although it can shorten the lifespan of someone who suffers from the disease. It’s treatable, but until now has only been curable by a bone marrow or blood stem cell transplant. Gene therapy might be able to change that. In fact, CNN has reported a complete cure in a very ill teenager in France.
But now things get more complicated. What if the therapy could be applied to a child before they were born? Pre-natal screenings can identify certain kinds of illnesses and conditions in the developing fetus. And there are some surgical procedures that are done in the uterus.
Could a gene therapy treatment even be done in this situation? Some current therapies use the subject’s own immune cells, tweaking them to recognize and attack cancerous cells, for example. However, a baby’s immune system is not fully developed at birth, so it seems like this kind of approach would be limited to certain diseases or conditions where the right kinds of cells were available enough and mature enough to be used.
Other gene therapies use special viruses to deliver their genetic payloads. Scientists have a pretty good idea how post-natal bodies, especially adult ones, respond to these viruses, but I wonder if anyone has much of an idea about how a fetus would react. And how would one ethically test such a therapy, or even how the fetus and the mother would react to the presence of the virus?
For couples using in vitro fertilization, the egg and sperm cells, before fertilization, and the earliest forms of the fetus, such as the blastocyst, are available outside the mother’s body. It’s possible to test the genes of the blastocyst before implantation.
In the US and other Western countries, doctors agree that creating “designer babies,” that is, babies whose genes are modified to produce certain desired characteristics, is unethical.
But a designer baby is very different from one whose parents’ genes have destined that child for some kind of serious disease or condition before or after birth. Scientists in China and the UK have demonstrated that they can make genetic changes at this stage of development, but none of the fetuses so modified allowed to continue to develop beyond a very early stage, where they still look like just a ball of cells.
Big Decisions for Parents
In the future parents will face some big decisions if a genetic test reveals a fixable abnormality, beyond the decision of whether to abort the pregnancy or not. Every choice will entail risks and doctors may not be able to say exactly how much risk each option holds.
Good parents want to do what’s best for their children. What will they decide? How will they decide? What social pressures will they face to either agree to the treatment or refuse it?
If you’re a parent, or want to be someday, what would you do? Please leave your thoughts in the comments box below.