Good evening all,
In class, we have talked a number of times about how our phenotype (our physical appearance and characteristics) stems from our genotype (the particular set of alleles that we have in our genome). We've also considered how phenotype and genotype are related, by examination of a handful of traits which are influenced (all, or mostly) by individual genes (such as the trait for freckles, or attached earlobes).
These examples allow us to evaluate the relationship between alleles (such as dominant and recessive forms), to consider patterns of gamete formation and potential crosses (via Punnett squares), and to assess familiar patterns of inheritance (via pedigrees).
These relatively straightforward examples suggest that other aspects of our genetic health, such as disease risk for a variety of conditions, might also be similarly simple: easy to diagnose, and potentially easy to fix, if problematic. Alas, this is not the case for most traits of human disease concern.
I'm forwarding here a link to an article which nicely describes why the genetic basis of our health is not so straightforward, or easy to manipulate. In reality, most of our important human diseases are only very weakly linked to individual genes, which themselves may play only a very small role in influencing our individual disease risk or expression.
So, of what value then is this massive Human Genome Project, this effort to sequence, and understand, every single one of our genes? Well, in short, we do not yet know its full value, as we are still learning how to mine this enormous database. It seems very likely to yield important insights into our genetic disease risks, but it has not led to the immediate creation of a broad spectrum of ready, easy-to-use, off-the-shelf treatments for our human diseases. That day of individualized, genetic approaches to health is coming, though - the first individually-based genetic treatments are now in use. They are as yet not broadly proven, and they remain enormously expensive. But, they represent proof-of-concept types of studies, which suggest that, as our knowledge and technology improve, the days of the 'genome card' are coming. Save some space in your wallets...
Have a great evening -