A hypothetical ethical quandary

A comment over at Pharyngula inspired me to ponder the ethical dilemmas that will arise as our ability to cure disease starts to encroach on the fine line between "different" and "pathological". In composing a reply, I came up with a thought experiment that I found compelling enough to warrant inclusion on my blog.

Imagine that a few decades from now, as the study of personal genomics advances, we find a mutation on the X chromosome that causes a slight difference in the sequence/amount of hormones that a woman experiences during pregnancy. And let's say this hypothetical hormonal fluctuation has two effects:

1) It makes her sons significantly more likely to be gay (and in fact, to make it interesting, let's say that scientists estimate that 40-50% of gay men's mothers had this particular mutation, whereas less than 10% of straight men's mothers have it, i.e. while not perfectly correlated, it is highly predictive of sexuality)

2) It causes a modest increase in her sons' risk of a rare type of testicular cancer.¹

Furthermore, let's assume that a simple, safe, and highly accurate screening process can be done for this, and it is cheap enough to be performed as a matter of course (in fact, the incremental cost is essentially zero, since in this not-too-distant future a mother-to-be's genome is routinely sequenced anyway to check for all sorts of other mutations of interest). And finally, let's say there is a safe, effective, cheap, easy "treatment" (e.g. a one-time hormone injection at a certain point in the pregnancy) that will bring the prenatal hormones in line with the "baseline" average in the majority of women.

So... do you offer it? Do you do it as a matter of course?

On one hand, it seems like the answer has to be a resounding "YES!"... The fetus is incapable of making medical decisions for itself, so if a prospective treatment carries little to no risk of (medical) side-effects, and reduces the fetus' risk of developing cancer later in life, even by a little bit, it would seem we are ethically bound to use it.

On the other hand, employing this treatment as a matter of course would significantly reduce the population of a traditionally-oppressed minority. It feels like an attempt to exterminate gays!

Furthermore, if you offer it as an option to mothers-to-be, is that even worse? Are you now allowing a mother to "hetero-ify" her baby without his consent?

I honestly do not know what my answer is to any of these questions. Luckily, this is (right now) nothing more than a flight of fancy. But I suspect we will be facing similar dilemmas in the near future. We are already facing it in regards to cochlear implants, which -- to the surprise of most hearing people, myself included -- have met with stiff resistance from many elements of the deaf community.²

Another hypothetical I mentioned in my Pharyngula comment is, what if we found a treatment that would cure mild cases of Asperger's -- and then, two decades after it started being used as a matter of course, we found ourselves with a shortage of engineers! As I mentioned in the opening paragraph, the line between "different" and "pathological" is not always clear. And, as the present thought experiment seeks to address, the phenomenon of pleiotropy may give us a single allele that simultaneously causes both a "difference" (and one we want to protect) as well as a "pathology"! These will not be easy questions.

Update: A commenter at Pharyngula points out that there is already an eBook with a virtually identical plot! More proof that there's nothing new under the sun, eh?

¹Lest this offend anyone, let me be perfectly clear that this is not a conjecture, nor is it meant to imply anything negative or to suggest that homosexuality is "deviant" or "pathological" or anything remotely of the sort. That ought to go without saying, but I am saying it anyways. I chose this scenario because current research strongly suggests that sexual preference has at least a partial genetic component, other research suggests that sexual preference can be influenced by prenatal hormones, and we also know that some hormones are implicated in certain types of cancer -- so the scenario satisfies a certain baseline plausibility, i.e. it doesn't contradict anything we know about the physical world, and I think that is good enough for a thought experiment.

²After watching a movie about it, I am much more understanding of and empathetic towards the anti-implant position... but I still think that, in cases where the child can expect significant hearing recovery from the implant, it's generally "the right thing to do". I will not pretend that it is an easy call, though, and my heart breaks for deaf parents who have to make this decision. If you were faced with an irrevocable choice that would give your child a valuable new ability, at the cost of possibly reducing the emotional and communal bond between you and her, at the cost of eliminating an entire realm of shared identification, would you do it? I'd like to say I would answer yes, but... I hope I will never have to make such a decision!