The Baylor Human Genome Sequencing Center first obtained the personal medical histories and three-generation pedigree of the volunteers. Then they performed next-generation sequencing on the part of the genome that carries the genetic blueprint for proteins.
Dr. C. Thomas Caskey is professor of molecular and human genetics at Baylor College of Medicine.
“We examined the DNA of the coding sequences — the exones — of individuals who wished to determine what their genetic risk was for adult-onset diseases.”
Members of the Houston chapter of the Young President’s Organization volunteered for the project. Dr. Caskey says many did so because they either knew they had a disease or a family member with the disease.
“The information that we developed from their sequencing actually verified 24 disease diagnoses in these individuals. That is, we could say, ‘alright, this disease you have, which might be breast cancer or thyroid cancer or diabetes or coronary artery disease, this can be explained by the DNA sequence of the gene that’s causative of the disease.'”
The study made sure that volunteers understood the implications of the research and the findings, as Dr. Caskey explains.
“Well, and that’s something that I’ve worked with them on. We did that in two ways: one, I met with everybody personally and went over all the data, and then of course they had a written report that detailed all the findings and suggestions on what should be done to modify their risk. It alerts their doctor that these people are at high-risk, you need to do as much as possible to avoid the onset of disease.”
The follow-up included that genetic counseling on how to modify the risk.
“Risk is determined genetically by about 50 percent. The other half of risk, which leads to the actual disease, is influenced very much by environmental factors — let’s say you’re obese or you have a high-fat intake or you don’t exercise. So risk of disease doesn’t make the diagnosis that you’ve got coronary artery disease, it says you are susceptible to coronary artery disease. Here are the ways we can intervene to avoid it.”
It’s hoped that sequencing could be a new risk detection approach to identify patients who may benefit from disease prevention surveillance — colonoscopys, mammograms and so on.