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What have we learned from the Human Genome Project?


Human Genome Project Results
Slight variations in our DNA sequences can affect things like whether we develop a disease. The single nucleotide polymorphism (SNP) is a common type of variation.
Slight variations in our DNA sequences can affect things like whether we develop a disease. The single nucleotide polymorphism (SNP) is a common type of variation.
Image courtesy Genome Management Information System, Oak Ridge National Laboratory

­Now that the Human Genome Project is over, it's time for scientists to examine the information produced and pursue related research. Much of the post-HGP focus has fallen on genes, spurring new discussions of how heredity works and causing scientists to lo­ok at DNA differently, setting aside the traditional focus on genes as the dominant actors within DNA. Some researchers are now looking at the 99 or so percent of DNA that aren't genes, wondering if these previously neglected chunks of the genome have significant roles to play.

­The HGP and subsequent research efforts have changed the consensus view of genes and noncoding DNA, casting them as part of an increasingly complex image of genes, DNA and other components of the genome. For example, epigenetic marks, the proteins and other molecules attached to DNA, are receiving more attention, especially for their apparent role in heredity. It seems that these marks can also pass on traits, just like genes, and misplaced or damaged epigenetic marks may increase someone's risk of developing cancer and other disorders [source: Zimmer]. A $190 million National Institutes of Health study hopes to map all epigenetic marks on DNA.

Along with changing how we think about genes, the Human Genome Project spawned lots of other projects. For example, in 2002, the International HapMap Project started charting SNPs among various ethnic groups. From person to person, the genetic code differs at around 10 million points (out of 3.2 billion DNA base pairs) [source: Aetna]. These differences are called SNPs -- single nucleotide polymorphisms. But despite these SNPs, human beings only differ from one another by about 0.1 percent, enough to ensure that no two human beings are genetically identical, even, sometimes, identical twins. Understanding SNPs can help us better understand genetic variation among individuals and ethnic groups; produce better genetic testing for predisposition toward disease; and contribute to the development of more personalized medical treatments.

Future projects and areas of research related to the HGP are seemingly endless. Many millions of dollars are being poured into projects like Encode, a massively ambitious effort to determine the role of every single piece of DNA in the human genome. (Encode stands for Encyclopedia of DNA Elements.) But while information yielded from the HGP and related projects will likely lead to important medical advances and disease treatments, the relationship between research and practical therapies isn't really one of simple cause and effect. Just one new drug can take 10 years of development time.

In the future, look out for these burgeoning fields of research, much of which owe a great debt to the work of the HGP:

  • Improved genetic testing to gauge predisposition for disease
  • Tracing genes to diseases and birth defects
  • Creating customized therapies based on genetic profiles
  • Manipulating or repairing DNA to stave off disease
  • The role of RNA, particularly the large amount of noncoding RNA

Despite all of these exciting discoveries and those that await us, we may never fully understand the inner workings of DNA. The rapidly shifting definition of the gene may be testament to that. One researcher told the New York Times that human biology could be "irreducibly complex" [source: Angier]. We humans can do and understand remarkable things -- launch spaceships, build incredibly fast computers, create gorgeous works of art -- but our 3.2 billion pieces of DNA may be too much for our minds to fully comprehend in the end. In the course of human progress, it has been far easier to understand the things we make, rather than what makes us.

­For more inform­ation about the Human Genome Project and other related topics like epigenetics, please visit the links on the next page.


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