Structural Biochemistry/Genome Analysis/The Impact of Genome Analysis on Medicine

The Ethics and Politics of Genome Sequencing and Science

"As in the most important scientific advances, the HGP carries with it benefits and problems. The benefits are immeasurable, and so are the problems. As DNA techniques provide important information on human genes, many diagnostic tools and therapeutic benefits, we do not know if the same information can also be used to discriminate against such individuals, employees and insurance companies. There is a very real prospect of insurance companies insisting on large-scale genetic screening tests for the presence of genes that conferred susceptibility to common disorders such as diabetes, cardiovascular disease, cancer and various mental disorders."¹

As we have seen in the past, controversy regarding stem cells, their origin, and their use has had political and scientific consequences. In 2001, President Bush banned the use of federal funds for later stem cell lines. Although this ban was later lifted, the political and human impact of science cannot be ignored; Science shows great promise with respect to human knowledge, technology, and power, but the gains we make through science carry with them great responsibilities. The freeze of federal funding on new stem cell lines significantly hindered scientific progress in a field that appears to show promise with respect to curing disease and improving the welfare of mankind, but it also serves as a reminder to the fact that science, for better or for worse, is intricately related to politics, and that our future scientific progress partly depends not on just scientists and their research, but on legislators and bureaucrats. Although DNA sequencing and genetic research is still a relatively new field, the implications of such knowledge carry social, political, and personal consequences in the field of medicine yet to be discovered.

In addition to the political relationship with science, technology, and medicine legally and financially, there are ethical considerations to be considered with new technologies. In the future, it may be possible to reliably clone human beings, artificially modify DNA to provide physical and mental benefits, and screen for "imperfections." The range of possible consequences of DNA analysis and manipulation technology is nearly infinite, and although it may be hard to forget the impact of scientific technologies and the power scientists already have today to manipulate DNA, it may be too easy to forget the responsibilities we have, both individually and socially, ethically and morally, with respect to the power we have and how we wield it. Whether there will be new laws passed regulating DNA with regard to how it is stored and used or whether there will be a new regulatory agency to protect against the misuse of DNA (through theft, sequencing, cloning, artificial manipulation, etc.) remains to be seen, partly because the technology is not widespread, and current capabilities are relatively limited by the lack knowledge we have about genes and multiple gene interactions and difficulties we have with respect to mammalian cloning.

In the future, however, this may change, and DNA manipulation on a mammalian scale may become very easy, especially with a greater understanding of how genes interact and what they do. What this will mean politically, economically, and ethically, is still anyone's guess. But as science drives new technologies, particularly with respect to DNA and gene manipulation, these questions will come into the public spotlight, as stem cell research has, and the consequences of such technologies will become more apparent and more profound.

Genome Sequencing and Medicine

Sickle Cell Anemia

A mixture of sickle cells and healthy red blood cells

The name Sickle Cell Anemia comes from the shape that the red blood cells take when affected with the sickle-cell trait. The sickle shape, which is caused by red blood cells being deprived of oxygen, causes the small capillaries to clog up, and impair blood flow throughout the body. This can result in painful swelling of the extremities when the capillaries clog up, and cause a higher risk of bacterial infection or stroke because of the poor blood flow. Also, sickle cells do not circulate throughout the body as long as regularly shaped blood cells do, thus leading to anemia because of a decrease in amount of blood circulating. This mutation, though unfavorable in other ways, is slightly beneficial in that this trait makes the infected persons resistant to malaria.

Sickle Cell Anemia is caused by a variation of one specific amino acid sequence in just one hemoglobin chain. This idea was proposed by Pauling, and proved to be correct later on. Around 7% of the world has some sort of disease of the hemoglobin that is caused by a variation in the amino acid sequence. Then, in 1956, Vernan Ingram proved Pauling correct by showing that the specific reason for the sickle cell trait was indeed the substitution of a single amino acid in hemoglobin, more specifically, of a valine substituting a glutamate in position 6 in the beta chain of hemoglobin. With the advancements in genome sequencing, the exact cause of these diseases can be discovered, thus becoming one step closer to discovering a cure. In this way, genome sequencing can be related to medicine, because it helps to find the direct cause of the disease, thus allowing researchers to look at more specific ways to correct the problems, instead of just the symptoms.

Thalassemia

Thalassemia is another disorder caused by a change in the normal genome. In this case, it is caused by a loss of a single hemoglobin chain instead of a substitution like in Sickle Cell Anemia. This disorder causes anemia, pale skin, and fatigue. The loss of the single hemoglobin chain can be found by genome sequencing. Thalassemia is an autosomal recessive blood disorder. Unlike sickle cell anemia, where the globin does not function properly, thalassemia is a condition where normal globulins are not produced in high enough quantities. There are three kinds of thalassemia: alpha, beta, and delta. Each is characterized by the inability to produce the appropriate globin chain. Like sickle cell anemia, however, thalassemia provides carriers some measure of resistance against malaria.

References

1. Falcón de Vargas, Aída. "The Human Genome Project and its importance in clinical medicine." doi:10.1016/S0531-5131(01)00570-2 <http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B7581-47W61Y4-BG&_user=4429&_coverDate=07%2F31%2F2002&_rdoc=1&_fmt=full&_orig=search&_cdi=12913&_sort=d&_docanchor=&view=c&_searchStrId=1094477520&_rerunOrigin=google&_acct=C000059602&_version=1&_urlVersion=0&_userid=4429&md5=a44d78db6508ff39d2670fc0ce486bb1#toc9>.

2. Stryer, Lubert, Berg, Jeremy M., Tymoczko, John L. "Biochemistry" Sixth Edition. W.H. Freeman and Company. 2007.