Today is officially dubbed by the National Human Genome Research Institute (NHGRI) as DNA Day, marking the anniversary of two genomic advances history: the discovery of the double-helical structure of DNA by Watson and Crick in 1953, and the completion of the Human Genome Project (HGP) by a collaboration of researchers in 2003. As a result of these scientific breakthroughs, we are currently living through a genomics revolution with life-changing medical advancements happening daily.
Watson and Crick’s discovery explained how DNA unwinds to eventually create the proteins that make up our bodies. The arrangements of four “letters” (or bases) on the DNA strands lay the groundwork for how our bodies look on the outside and how our organs work on the inside. Without this knowledge, mapping out the entire set of DNA in a human (known as a genome) would not have been feasible. Enter the initiation of the HGP, back in 1990. Using a “shotgun approach,” large chunks of overlapping DNA were sequenced at a time in order to tackle the assembly of the approximately 3 billion base pairs that make up the human genome. The project took nearly 13 years and $3 billion to complete, owing a large thanks to a program allowing publicly accessible data and a “friendly” competition between private and public sectors. Since this time, computer-automated sequencing methods, bioinformatics for storage and analysis of data, and next-generation sequencing technologies have led to a rapid acceleration of the genomics field. Currently, millions of base pairs can be analyzed in one day and the cost to sequence an entire human genome dropped from $100 million in 2001 to less than $2 thousand in 2015.
With increased accessibility to knowledge and understanding of genetics, new treatments are in development to help treat, prevent, and, in some cases, ameliorate disease. One such treatment, often making today’s headlines, is gene therapy. You may have heard of CRISPR/Cas9 being used as a technique to insert correct segments of DNA into cells with mutations. Gene therapy is not a new concept. It has been used to treat disease since 1990, when Ashanti DeSilva, a patient with severe combined immunodeficiency (SCID), was effectively treated with genetically-modified white blood cells. In 2013, there were 1,000 gene therapy trials in the United States alone. Though promising, the ability to essentially cure disease with gene therapy is still out of reach. There is the potential that CRISPR/Cas9 can one day be used to insert the correct DNA sequence at the point of conception to completely prevent an inherited disease from affecting a child before they are born.
Pharmacogenomics is another focus benefitting from the technological advances post-HGP. The idea is that, by knowing your personal genome, specific drugs can be used to more effectively treat a certain disease, such as some cancers or heart problems. Certain drug-resistance genes can be identified in an individual, allowing specific therapies to be developed to treat these individuals. Herceptin is one such drug specially designed for a subpopulation of metastatic breast cancers based off of the tumor’s genetic profile. The future of personalized medicine envisions a medical concept of providing the right drug at the right dose for the right person at the right time.
We have come so far since the initiation of the HGP. Gene therapy and pharmacogenomics are a small representation of the many areas of genetic research that continue to improve since the project’s completion. With new treatments and testing options becoming more accessible to the public, it is becoming even more important to have the guidance of a genetics professional to help make sense of the impact of genetic research on your health. Genetic counselors have expansive knowledge of genetics and are skilled at educating and supporting individuals and families who are looking to utilize genomic medicine.
Tara Jones is a graduate student in Northwestern University's Genetic Counseling Program.