By Dave Gardner
The Geisinger Health System’s MyCode Community Health Initiative is studying patient samples of deoxyribonucleic acid (DNA), the simple but complex storehouse of biological information within humans, in an attempt to prevent and improve treatments for disease.
Most DNA is located in the nucleus of every cell in the body, and the vast information within the DNA is stored as a code made up of the four chemical bases adenine (A), guanine (G), cytosine (C) and thymine (T).
Within human DNA, these AGCT segments create about 3 billion bases and more than 99 percent of these are the same in all people. The order, or sequence of these bases determines the information available for building and maintaining the person, plus variances between people such as hair color.
MyCode was officially launched in January 2014, in collaboration with the Regeneron Genetics Center and it was originally set out to recruit 100,000 study participants. This numerical target was reached in only two years and the study’s managers are now setting their sights on at least 250,000 participants who volunteer to donate a DNA sample during routine blood tests.
Geisinger is returning DNA study results to patients who are at risk for 27 medical conditions that have been identified by their gene sequences. NEPA has an unusually stable population often consisting of three or more generations and this factor has made the region a superior location for such an extended genetics study.
As a large regional health system, Geisinger has another advantage due to the existence of comprehensive electronically-stored health information from patients over a lengthy time span. This data enables MyCode researchers to match specific gene variations with health problems and subsequent patient outcomes and to also project the possibility of disease for the descendants of those patients whose DNA is being studied.
Cardiac disease risk
MyCode has proven it can save lives. Jody Christ, 61, Elysburg, a day-care worker and administrator for her husband’s business, was approached by Geisinger at a routine appointment and asked if she would like to participate in the genetic study. She agreed and donated a blood sample that was stored while it awaited DNA sequencing.
Christ already knew she carried a health risk, because of a history of extremely high cholesterol that seemed to be apart from dietary influences. During a January 2016 check-up with a Geisinger physician Christ had been informed that the elevated cholesterol had to be addressed, but the situation became complicated because of side-effects Christ experienced from the required medication.
Attempts to ride a stationary bike and to walk left Christ with arm pain, nausea and shortness of breath. However, before the situation could further escalate Christ was informed by the MyCode team that she carried a gene which increased her risk for heart attack by a factor of 20.
“Geisinger quickly swung into action and I was diagnosed with angina, and although my EKG was normal they found three heart blockages from 50 percent to 90 percent,” Christ said. “I soon had triple-bypass surgery and it definitely saved my life.”
As the recipient of life-saving technology from MyCode, Christ believes that if everyone had their DNA screened it would save many lives. This is also true for a person’s extended family, because the troublesome genes that can predispose a person to specific disease often reappear in various members of a genetic tree.
“My daughter has been urged to be involved with MyCode as well as my extended family,” said Christ. “You can also bet I’m going to be extra vigilant in the future, and be sure to take medication to control my cholesterol.”
Andrew Faucett, M.S., licensed genetic counselor and professor and director of policy and education for research with Geisinger, noted that mass use of MyCode has been made possible because of steadily decreasing costs for gene sequencing. This reality, along with NEPA’s multiple-generation families plus Geisinger’s use of electronic medical records, all make the region attractive for genetic study.
“MyCode was coasting along with minimal funding from state and internal dollars until we partnered with Regeneron, who has one of the country’s largest labs for gene sequencing,” said Faucett. “Costs dropped and we have a goal of including all of our patients.”
Fortunately, the MyCode researchers do not have to sift through all three billion-plus human genes, known as the genome, as they attempt to identify people at risk for the multiple diseases covered by the study. Only the DNA, called the exome, which is the 20,000 gene root recipe for creating a human, is studied.
“Of these 20,000 genes in the exome, we have come to understand 2,000 to 3,000, and are working on the other 17,000,” Faucett said. “Specifically, MyCode is focused on 76 genes that cause 27 medical conditions and in the future we hope to expand this number.”
According to Faucett, 270 results have been returned to MyCode participants warning them of genetic predisposition to one or more of the 27 diseases. This information can also be other
family members, with the elderly especially interested in what they may have passed along to their descendants.
Faucett added that a global explosion in underway regarding DNA research and its key role in understanding life at the molecular level. Currently, MyCode is not evaluating genes suspected of causing predisposition to behavior or mental illness, such as Alzheimer’s, because environmental factors also play key roles in the onset of these conditions and in many cases no medical options exist for prevention.
“Genetic research is changing health care, because we often do not have to wait until a patient actually becomes sick,” said Faucett. “This is new ground for medicine, and when you have an altruistic population that participates such as we have within NEPA, a program like MyCode can save a lot of lives.”