A View from Susan Young Rojahn
A Decade of Advances Since the Human Genome Project
Despite breakthroughs in technology and medicine, there’s still a lot of work ahead for understanding and using the human genome.
This Sunday, the National Institutes of Health will celebrate the 10th anniversary of the completion of the Human Genome Project. Since the end of the 13-year and $3-billion effort to determine the sequence of a human genome (a mosaic of genomes from several people in this case), there have been some impressive advances in technology and biological understanding and the dawn of a new branch of medicine: medical genomics
Today, sequencing a human genome can cost less than $5,000 and take only a day or two. This means genome analysis is now in the cost range of a sophisticated medical test, said Eric Green, director of the National Human Genome Research Institute, in a teleconference on Friday. Doctors can now using DNA analysis to diagnose challenging cases, such as mysterious neurodevelopmental disorders, mitochondrial disease, or other disease or unknown origin in children (see “Making Genome Sequencing Part of Clinical Care”). In such cases, genomic analysis can identify disease-causing mutations 19 percent to 33 percent of the time, according to a recent analysis.
Genomics is possibly making its biggest strides in cancer medicine. Doctors can now sequence a patient’s tumor to identify the best treatments. Specific drug targets may be found in as many as 70 percent of tumors (see “Foundation Medicine: Personalizing Cancer Drugs” and “Cancer Genomics”). The dropping price of DNA sequencing is also changing prenatal care. A pregnant woman now has the option to eschew amniocenteses or other invasive methods for checking for chromosome aberrations in her fetus. Instead, she can get a simple blood draw (see “A Brave New World of Prenatal DNA Sequencing”).
Before the Human Genome Project, researchers knew the genetic basis of about 60 disorders. Today, they know the basis of nearly 5,000 conditions. Prescriptions are also changing because of genomics. More than 100 different FDA-approved drugs are now packaged with genomic information that tells doctors to test their patients for genetic variants linked to efficacy, dosages or risky side-effects.
But the work for human genome scientists is hardly over. There are still regions of the human genome yet to be sequenced. Most of these still unyielding regions are in parts of chromosomes that are full of complex, repetitive sequence, said Green. The much larger challenge will be to decipher what all the A’s, T’s, G’s and C’s in the human genome mean. Only a small proportion of the genome encodes for proteins and there is ongoing debate as to how much of the remainder is functional or just junk or redundant sequences. And many scientists agree that the advances in medical genomics are just the tip of the iceberg— much more work lies ahead to fully harness genomic information to improve patient health.
You can see more of the numbers behind the advances in genome science since the Human Genome Project in this chart published by the NHGRI on Friday.