2009-01-09

BBC: 'Inflicting' Cancer on Your Children

A news item out of Britian is being widely reported today. It concerns the preimplantation evaluation of an embryo for the presence of a mutated BRCA1 gene. Mutations of this gene can dramatically increase the risk of breast and ovarian cancers.

The women in the family of the 'cancer-free' infant's father had been diagnosed with breast cancer in their 20's for three generations. And while the fertility expert, Paul Serhal, who cared for the couple is right in saying, "The lasting legacy is the eradication of the transmission of this form of cancer that has blighted these families for generations," this legacy comes at a cost.

In general, prenatal genetic testing poses a risk to the pregnancy and to the health of the fetus. Then there is the issue of what to do with the information if the fetus tested positive. Abortion? Prophylactic mastectomy and oopherectomy (precautionary removal of undiseased breasts and ovaries) when the girl completes adolescence? These maneuvres carry their own health risks.

In this case, preimplantation evaluation was done. Multiple embryos were created from the parents' gametes (sperm and eggs) in a lab, and then tested for the mutation. The winning embryo of the implantation lottery gets the privilege of gestating. This technique has the advantage of avoiding a decision about abortion or later decisions on prophylactic surgery.

I considered becoming a medical geneticist when I started my medical career. The science is fascinating, and builds upon my undergraduate genetics degree. But I did a summer as a student working in a medical genetics clinic and found the profession profoundly frustrating. Here were people of all ages for whom you could diagnose a condition that you could rarely do anything about.

Conditions like phenylketonuria and other inherited disorders of metabolism notwithstanding, medical genetics is essentially a diagnostic specialty with virtually no opportunity for treatment. You can tell people that they will develop Huntington disease, a debilitating progressive neurologic disorder, but you can't prevent or forestall it. You can diagnose them with Marfan syndrome and warn them of the possibility of a fatal aortic dissection. Can't correct the problem. You can diagnose them with BRCA1 or 2 mutations and advise them of the near certainty that if they live long enough, they will develop breast or ovarian cancer. The solution? Mastectomy and oopherectomy.

The really egregious thing about the BBC report that prompted me to start this post in the first place was Serhal stating, "The parents will have been spared the risk of inflicting this disease on their daughter." Serhal's biases are exposed here. He appears to feel that carriers who do not take the precaution of screening their embryos are deliberately causing them harm. If he had used the word "transmitting" instead of "inflicting," I would have no quarrel. But he didn't. He implies the recklessness of parents without the scruples of his clients, if not outright maliciousness.

Is he right? Are parents with the mutation who don't get their embryos tested "inflicting" the condition on their children?

While Serhal eagerly accepts the accolades of his accomplishment, consider the implications of this innovation, good and bad. The world is imperfect, and any interested observer can see that our solutions often lead to new problems. What about the cost, risk, and invasiveness of the procedure? What about choosing not to conceive? What about adoption? What about the precedent? The vilification of choosing to conceive naturally? Will criminalization be far behind?

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