In Defense of Selection for Nondisease Genes

John Robertson supports preconception sex selection, given certain constraints. I have elsewhere defended pre- and postconception sex selection, with fewer caveats, against a different range of objections (Savulescu 1999; Savulescu and Dahl 2000).

Sex selection is an important issue because it is the first example of selection of nondisease gene/s. A disease gene is a gene which causes a genetic disorder (e.g., cystic fibrosis) or predisposes to the development of disease (e.g., the genetic contribution to cancer or dementia). A nondisease gene is a gene that causes or predisposes to some physical or psychological state of the person that is not itself a disease state, e.g., height, intelligence, character (not in the sub-normal range).

Robertson's support for preconception sex selection can be extended to selection for nondisease genes and strengthened. Robertson relies on a number of contentious (but defensible) empirical claims. I argue that he need not rely so heavily on these claims and that moral principles go a long way to supporting selection of nondisease genes. Here I will argue that couples should be allowed to select nondisease genes even if it results in a child whose life is worse than that of children not born as a result of slection. I will also argue that we should allow selection for nondisease genes even if this maintains or increases social inequality, at least in those cases in which the nondisease gene has a significant positive impact on well-being.

Well-Being of the Child

A major objection to selection for nondisease genes is that it will cause harm, such as psychological distress, to the offspring, especially in those cases when the technology fails and parents do not get the child they expected. Robertson's response is to argue that other parents have such expectations and counseling will lessen the impact of frustrated expectations. Robertson thus relies on the empirical claim that sex selection will not result in children being born who have worse lives than children not born as a result of sex selection.

The underlying moral principle here is that an intervention, such as sex selection, is wrong if it results in children who are worse off than children not born as a result of that intervention. I call this moral principle the Maximising Constraint. This moral principle is often thought to fall out of the "Best Interests of the Child" Principle. This is a most important guiding principle of many of the laws governing reproductive technology. For example, in Australia, the Victorian Infertility Treatment Act 1995 states "the welfare and interests of any person born or to be born as a result of a treatment procedure are paramount."

The Maximising Constraint does apply to some cases. Consider a hypothetical case of genetic manipulation. Imagine that the genetic pathway of determination of sex is understood. A couple has two boys. They now want a girl. The woman is forty. She has in vitro fertilization (IVF) but only produces one male embryo. Doctors inject anti- testis-determining-factor into the embryo. This changes the male embryo into a female embryo. This procedure mirrors a biological process that infrequently occurs in nature and results in an "intersex condition" (an XY female). The child, Sarah, is an apparently normal female. However, she has male genes. Later Sarah grows up and discovers she has one abnormality: her ovaries are abnormal (gonadal dysgenesis), and she cannot have children by normal means. She becomes distressed and resents her parents' interference in nature.

Was Sarah harmed by her parents' genetic manipulation? Someone is harmed by an act if she is made worse off by that act's being performed than she would otherwise have been. In this case, if Sarah is considerably disturbed by the consequences of her parents' actions, she is worse off than she would have been if her parents had not altered her gender. So...