Thursday, January 10, 2008

Genetic Justice Must Track Genetic Complexity (Now Published)

My paper "Genetic Justice Must Track Genetic Complexity" is now available in the latest issue of the Cambridge Quarterly of Healthcare Ethics. Here is a sample:

Genetic inequalities permeate our societies. These inequalities are not quantitative inequalities; rather they are qualitative inequalities. Justice is concerned with both kinds of inequalities. Economic inequalities are the most common form of quantitative inequalities. People can have differing amounts of wealth and income. But this does not exhaust the scope on inequalities justice seeks to address. Inequalities in opportunities for education, for example, are typically qualitative inequalities rather than quantitative ones. Children may receive the same number of hours of instruction but the quality of instruction they receive could be very unequal. Similarly, although all citizens have approximately the same quantity of genes (estimates suggest there are between 20,000 and 25,000 protein-coding genes), the quality of our genetic constitutions can vary significantly.

Unlike socioeconomic inequalities, which are a mix of both brute luck factors (e.g., natural endowments, social position, etc.) and choice (e.g., consumption habits, attitudes toward saving and work, etc.), genetic inequalities are 100% brute luck. We inherit our genetic endowments from our parents, and they inherit theirs from their parents, and so forth. No individual is responsible for the genetic endowments he or she is born with. Furthermore, the life prospects for the least advantaged in the “genetic lottery” of life are often extremely grim.

Consider, for example, that in America the average life expectancy is around 77 years of age. That number will vary depending on factors like gender, race, and wealth. Although these factors influence the life prospects of Americans, none of them come close to the extent to which genetic variations impact the life expectancy of the worst endowed. Americans born with average genetic constitutions can expect much greater life prospects for things like health, longevity, and intelligence than those born with the worst genes. Children born with infantile Tay-Sachs will die by five years of age. People born with a mutation of the FMR1 gene will develop Fragile X Syndrome, the symptoms of which can vary from slight learning disabilities to mental impairment. No one deserves the genes they are born with. The results of the “genetic lottery” are arbitrary, and they are often tragic, both for the victims themselves and their loved ones and families.

The prevalence of the worst genetic disorders, like infantile Tay-Sachs, is extremely small. But there are over 6000 known single-gene disorders, which occur in 1 out of every 200 births. “A single-gene disease is a disease caused by a single malfunctioning allele. Such diseases typically can develop in practically all usual environments.”

The most prevalent diseases—like heart disease, cancer, and diabetes—are not caused by a single malfunctioning allele. These more common diseases are multifactorial diseases. Their development depends on a variety of factors beyond our genetic constitutions. Environmental factors like diet and lifestyle (e.g., exercise, smoking, stress levels, etc.) often play a more important role in determining our risk of developing multifactorial diseases. The American Heart Association estimates that, in the year 2001, 64,400,000 Americans had one or more forms of cardiovascular disease. Cardiovascular diseases are responsible for 1 out of every 2.6 deaths. Coronary heart disease caused 502,189 deaths in 2001 and is the single leading cause of death in America today. This is followed closely by cancer. Taken together, heart diseases and cancer account for over half of all deaths in America. Our genes do play a role in our susceptibility to multifactorial genetic disorders. For instance, inheriting faulty BRCA genes gives women a greater risk of developing breast cancer. But for many debilitating conditions, environmental factors play a much greater role in our susceptibility to disadvantage.

What will the demands of distributive justice be in the postgenetic revolutionary society? Where do the current and possible future benefits of biomedical research figure in an account of justice? These are questions we must begin to grapple with if we hope to institute a just regulation of new genetic technologies. But we must ensure that our desire to mitigate genetic disadvantage is tempered by an appreciation of the fact of genetic complexity as well as a recognition of the other demands of justice (e.g., the duty to mitigate other forms of disadvantage, respect for reproductive freedom, etc.).