There’s nothing like ignorance to fuel a controversy, even if it’s scientific ignorance. A controversy is brewing over the idea of personalized medicine based on the analysis of an individual’s genome through genome-wide association studies, or GWAS. Enabled by the ever decreasing cost of analyzing the human genome, some scientists believe it is possible to tease out of the genomic data a useful and reliable analysis of a person’s genetic weaknesses – leading, presumably, to preventive measures. Other scientists say, “Balderdash.” (Or something like that.)
At issue is the degree of ignorance. Those in favor of GWAS admit that there is much we don’t know about the human genome or the effect of defects in specific genes, but that what we do know is useful. Those who are skeptical say we know so little, even about genes we think we know, that it’s misleading (or even dangerous) to believe that diagnosis and preventive measures are realistic. This is really a wonderful argument to follow: It can reveal much about the process through which science tries to move from ignorance to knowledge (and it ain’t pretty); it can help expose the rising fraud associated with genome analysis; it provides an entry point into the rapidly developing world of molecular genetics; and it’s important because ‘personal genetics’ – if and when it is substantially trustworthy – will have profound impact on personal health, social issues of health management, and challenge the ethical foundations of child-bearing.
The core of belief in GWAS is that by analyzing the entire genome of an individual, analysts can spot genes that are associated with various disorders. For example, the BRCA1 gene variant associated with breast cancer. Which genes are spotted and what disorders are associated with them is obviously dependent on continuing research. Few are disputing that having certain genes may indicate a tendency to develop certain disorders. The problem, as seen by the skeptics, is that most of the genome consists of genes and gene sequences for which we have (as yet) no idea what they do AND for those genes where we have found associations with specific disorders, we may not correctly understand the nature of the correlation. As Carl Zimmer put it in his blog The Loom:
The genetic roots of common disorders, like high blood pressure and Alzheimer’s disease, have proven to be a lot more complex. It’s possible that the risk for some common diseases may be the result of variations on hundreds of genes, with each variation contributing a tiny fraction of the risk, and different combinations able to cause just as much of the disease. It’s also possible that the risk for some diseases is due to very rare mutations, each of which has very strong effects. There may be a lot of these rare mutations in the world’s population, making it hard to find them all and figure out what they do.
[Source: Discover Blogs]
Because so much of the argument is based on ignorance, it’s predictable that there won’t be any ‘winners’ or ‘losers’ – there will only be changes to the argument based on the advance of knowledge. Science will learn more about which genes are associated with what disorders. It will, eventually, show at the molecular/chemical level what underlies these associations. It will also, probably, reveal far more complexity in the interplay of genes (both coding and non-coding), RNA, protein formation, and the general chemical ecology of the cell. As the scientific process goes along, some gene associations will drop out, some will become reinforced, and others will become confused. Whether any kind of action should be taken based on these kinds of findings – well, that’s an issue for ethicists, profiteers, and the medical community (among many) to hash out.
In any case, this is a controversy very much worth the tracking in SciTechStory.