In narrowing a difficult diagnosis while choosing medications and advising the patient, an accurate family history can offer valuable insights. However, getting one isn't always simple.
At a time when contact with one parent or extended family may be limited, and adoptions and fading memories make reliable information scarce, putting together an accurate family history from patient interviews can be difficult.
Fortunately, as genomic medicine becomes integrated into medical practice, physicians will have evidence-based data to evaluate genetic predispositions.
The sticking point is that although the cost of genomic sequencing has come down, insurance often doesn't cover its use for preventive medicine. For many patients, the out-of-pocket cost for medical genomic testing can still be a bit steep for routine use.
Enter FDA approval for direct to consumer genetic health reports provided by services like 23AndMe. People can upgrade their $99 ancestry reports to include a wide range of genetic health information for $199. For $10 more, they can upload that data to Promethease for a more detailed report comparing their data to a large SNP database.
Physicians will likely soon will be seeing more printouts from direct to consumer genetic testing. Well managed, they can be a helpful resource. Poorly managed, the volume of information can be overwhelming.
On the plus side, low cost direct to consumer health reports can alert patients and their physicians to higher risks for gastric complications from NSAIDs; myopathy associated with statins; poor response to warfarin; lactose intolerance; celiac disease; macular degeneration and a long list of other markers including the APOE4 variant linked to late onset Alzheimer's and coronary artery disease, and variants in LRRK2 and GBA linked to Parkinson's Disease.
Reports also include carrier status for a range of inheritable diseases to help couples planning to have children who have concerns about conditions that run in their families. The reports include carrier status for Cystic Fibrosis, Sickle Cell, Tay Sachs, Sjogren's syndrome and a number of other disorders.
Other reports physicians might find helpful include predispositions to more subtle health factors patients might not be inclined to self report, including an inclination to sleep disturbances.
When combined with a Promethease upload, the patient's individual data can be compared to a large SNP database for correlations to several types of cancer, heart disease and a wide range of other disorders.
The challenge lies in making sense of all this information and helping patients understand what to do with it.
"First, it's important to verify the reliability of the data and the source. We may also need to protect patients from opportunists who try to sell them supplements and remedies that haven't been proven effective," UAB Chief Genomics Officer Bruce Korf, MD, PhD, said.
The physician's role in managing the big picture of the patient's health and genetic risk is vital. There are so many different genes that what might help reduce risks for one variant could be exactly the wrong thing for another.
"The integration of genomics and medical practice offers a tremendous potential for improving outcomes with more precise, personalized treatment. It's a rapidly emerging field, and those of us in genomics are working with physicians to help them make effective use of this new information," Korf said.
Even better than low cost testing, Alabama residents can get free testing through the Alabama Genomic Health Initiative.
"UAB and HudsonAlpha Institute for Biotechnology are gathering a genomic database of 1,000 volunteers from all 67 counties in Alabama," Korf said. "Though their physicians, those who participate will receive reports on 59 genetic markers for diseases with actionable treatment options. If a patient is positive for one of these markers, our genomics specialists and genetic counselors are available to assist physicians and patients in making the most effective use of this information."
For details about the initiative and how to participate, go to UABMedicine.org/AGHI.
Both 23AndMe and Promethease have extensive cautions about interpreting data and accessing genetic counseling when needed. Those who order the tests can choose whether or not they want to know about their status for APOE4 and Parkinson's Disease markers.
So what does a patient and physician do when they receive a report showing APOE 4/4 alleles? There are treatments to reduce the risk of coronary artery disease, but treatments to address the high risk of late onset Alzheimer's are still elusive. Hopefully soon, new treatments will be on their way.
The Titanic could have missed the iceberg if they had changed course in time. Knowing the iceberg is there can help patients begin to make small changes early to reduce risks. An active area of research is studying how carbohydrates and different types of fats are handled differently in the brain depending on which alleles are in the patient's genome. Antioxidants and omega 3s seem to show benefits in some studies, and there are reports that some types of exercise influence epigenetic changes that can modify risks. Studies of brain trauma and neurodegenerative disorders also suggest that reducing the risk of concussions and other brain injuries could be particularly important.
The more we know about the genes that spell out human life, the more we learn about how to correct misspellings and the best individual treatments for the most effective outcomes.
Bruce Korf MD PhD