There is one fundamental question that has been nagging on me since grad school: Where is the seat of the soul in the human genome? Thanks to the relentless search of several groups of scientists [1, 2, 3, 4, 5] , with some help from Francis Collins, we now know the answer: it resides on chromosome 9p21.
This is what we learn when reading an article by Nicholas Wade in the online version of The New York Times. This topic also has been blogged before, on The Tree of Life and on iBiome. Here is some background: Myocardial infarction and type 2 diabetes are unrelated multifactorial diseases that are thought to have a genetic component. Since both conditions are severe and quite common, many groups are out to find so-called susceptibility genes, these are gene variants that have a marked influence on the likelihood to contract the disease.
In a series of papers published in Science, two groups found a remarkably strong association between a particular SNP marker (rs10757278) and the risk for getting myocardial infarction. Three additional papers reported on an association between another SNP marker (rs10811661) and the risk for type 2 diabetes. The interesting bit is that the two SNP markers are in very close proximity to each other on human chromosome 9p21.3 . The SNPs are not part of a known or suspected transcript, but rather sit in the intergenic region close to the gene for the cell cycle inhibitor CDKN2A/2B.
The fact that susceptibility genes for two important diseases lie so close together on the genome prompted Francis S. Collins to coin the remarkable phrase
“I think this is a stunner. This is like the seat of the soul of the genome”
(cited according to the NYT article). In the same article, Kari Stefansson of DeCode is quoted saying that the two diseases are uncorrelated, suggesting that the close proximity of the susceptibility markers might be a mere coincidence.
There is a saying that in research, for each question answered several new ones arise. What is troubling me now most is where to look for the brain of the genome? And there is a related question, but that one is easy. It must be somewhere on the Y chromosome.