A growing understanding of human genetics holds the promise to dramatically change healthcare through customized preventative care and treatments.
- Our health dictated by our genetics: The percentage of our health dictated by our genetics and the faction by behavior and environment depends on individual diseases. Some diseases are entirely genetic and they are called 100 percent penetrant. Diseases such as Huntington’s disease, cystic fibrosis, sickle cell anemia, Tay-Sachs disease and Downs syndrome are purely genetic. Other, more complex diseases such as Type 2 diabetes or rheumatoid arthritis have a significant behavioral component. That means that even if a person has a genetic predisposition towards the disease there is a lot one can do behaviorally to prevent it. Complex or multifactorial diseases often have several genetic components as well as several behavioral components. For example, there are now at least a dozen known genes that can contribute to Type 2 diabetes. This is because there are many pathways that lead to the disease. Decreased production of insulin, decreased secretion of insulin and decreased response to insulin are the most common.
- Understanding the way specific genetic variants influence individuals’ disease risk enable awareness and possible prevention or treatment: If someone knows that they have genes predisposing them to a particular disease, then they can be more vigilant to other symptoms of that disease. For example, if someone has certain alleles of the gene for clotting factor F5, it could be an indication that the person might be at a high risk of developing deep vein thrombosis (DVT) and one should perform a test of their thrombin levels. This is very important as DVT can lead to strokes and pulmonary embolisms resulting in death. Other examples are familial breast cancer. If a person has a family history of breast cancer and genetic tests indicate that they have one of the BRCA 1 or BRCA 2 mutations, then they should make sure that they have regular mammography exams. Finally, if one has two or three of the genes that predispose them to Type 2 diabetes, they should watch their weight, exercise regularly and have their blood glucose measured routinely.
- Knowing his own genetic profile helps reduce healthcare costs and motivate patients to make healthier decisions: Preventive medicine is always the best and least expensive medicine. We currently use vaccines to prevent many infectious diseases. This is far less expensive and much better for the patient than using antibiotic or anti-viral treatments to try to cure an infection. The risks are also substantially lower with vaccines. Much of the cost of the current health care is due to expensive diagnostic methods and interventions for patients who already have a disease. So preventing the disease in the first place is by far, the best way to reduce health care costs. Hopefully, genomics and genetic testing will do for inherited disease what vaccines have done for infectious disease. I see genomics as being the way toward preventing the manifestations of inherited disease. More importantly, the cost of sequencing is coming down so fast that in the next three to five years we will be able to determine the complete genome sequence of every individual at birth for less than $1,000. This genomic information, coupled with our knowledge of the genes causing disease mentioned above will give people a genetic roadmap of their potential inherited diseases. Preventing disease will also become the responsibility of the patient. He will know what the risks he takes if he smokes, over-eats or leads a sedentary life style. The risks will be personalized based on his own genetics.