Whole-genome sequencing could help researchers identify disease risk in specific patients and see how well they will respond to certain drugs, but the technique still needs some work.
The process works when researchers determine " the sequence of the billions of building blocks, called nucleotides, that make up [the patient's] DNA", a Stanford University Medical Center news release reported.
In order for this technique to be successful, researchers determined improving sequencing accuracy in disease-associated genes is a key factor. The team also has a grim outlook on the monetary cost of the process in the near future.
"We need to be very honest about what we can and cannot do at this point in time," said Euan Ashley, MD, associate professor of medicine and of genetics, one of three senior authors of the paper. "It's clear that if we sequence enough cases, we can change someone's life. But with this opportunity comes the responsibility to do this right. Our hope is that the identification of specific hurdles will allow researchers in this field to focus their efforts on overcoming them to make this technique clinically useful."
The team looked at the genomes of 12 healthy people and looked at the degree of sequencing accuracy necessary in making clinical decisions on the case.
The team estimated a cost of $17,000 per person to sequence their genome and look at the genetic variations that would be necessary in determining if a follow-ups was necessary.
Although there are clearly challenges in bringing whole-genome sequencing into the clinic, this finding was clearly medically significant," Postdoctoral scholar and cardiology fellow Frederick Dewey, MD, said in the news release. "It's not possible to predict from a study of 12 people how often this type of clinically actionable discovery will occur, but it definitely supports the use of this technology."
The team also found modern genome-sequencing tests to not accurately identify disease risk in between seven and 16 percent of genes. This can cause medical staff to miss a disease risk or could lead to false alarms.
"These off-the-shelf genome sequencing techniques were developed to provide generally good coverage of most of the genome," Dewey said. "But there are some regions that remain to be covered well that we care very deeply about. We still need to supplement this information with additional sequencing in some regions to make clinically usable decisions."
The team found the amount of manual labor required to sift through each gene variants was about 100 hours.
"It remains significantly harder to use whole-genome sequencing for disease prediction than for disease diagnosis," Dewey said.
The researchers hold that while affordable and efficient genome sequencing may be a long way off, it is still worth pursuing.
"Our intention in doing this analysis was to draw a line describing where we are with this technology at this point in time and identify how best to move forward," Ashley said. "Things are becoming more clear, and the challenges to bringing this technique to the clinic are becoming crystallized. Whole-genome sequencing has the power to be absolutely transformative in the clinic."
