I’m sure we’ve all read great science fiction involving the benefits and potential downsides to genetics. Some warn of the dangers of genetic manipulation or testing, while others revel in the idea of being able to effectively reprogram yourself (note to self: avoid genetic programs written by Microsoft.) But as you might expect, time and science marches forward and some of the genetic issues we’ve only read about are actually coming to pass.
For example, there is a new set of testing called Preimplantation Genetic Diagnosis (PGD) that allows you to look for things in an embryo before it is implanted into the womb. Testing for things like spinal muscular atrophy – a terrible, painful, and unavoidably terminal condition that affects babies. If you fear you might have a baby with this condition, you’re best bet is to undergo the now routine in vitro fertilization process with a twist – you test the embryos for genetic issues before implantation. Sounds like a good way to avoid a host of potentially deadly genetic disorders – but what about other testing? For example, you can now test for the susceptibility to colon cancer. Certainly a bad disease, but having the gene doesn’t mean you get the illness and the situation it isn’t untenable for life – so should we select against it? And what about deafness? That’s another genetic disorder that can be screened out. Is it ethical to do so, or is this eugenics?
And then there is sex – many people want to have a baby of a particular sex for reasons ranging from the simple desire to have one of each to complicated social issues. PGD allows this – and it isn’t science fiction. A survey done last year shows that nearly 10% of all PGD treatments were done to select the sex of the baby. And while no statistics are kept as to the choices made, there is anecdotal evidence to suggest that as many as 90% of selections are for male children. If that’s true, its disturbing. So far it doesn’t impact the overall gene pool as the number of PGDs done today is still relatively small (in 2005, 5000 PGDs were done out of 4 million babies born.)
How far away is the world of Gattaca? Is it right to discard an embryo because it doesn’t have some characteristic you want? What things might be selected out of the gene pool this way? It’s an interesting question – just try to avoid any unwanted human-animal hybrids.