Drs. Rahul Desikan and Leo Sugrue Discuss Genomic Medicine and Neurogenerative Diseases
“If a crystal ball could reveal your personal risk for developing heart disease or breast cancer or Alzheimer's disease, would you pay to take a look?”
This was a question asked by Rahul Desikan, MD, PhD, and Leo Sugrue, MD, PhD, in an opinion piece recently published in Scientific American. For Dr. Desikan, the answer was overwhelmingly “yes.” As up-and-coming neuroscientists and neuroradiologists, he and Dr. Sugrue became fast friends and research partners at the UC San Francisco Department of Radiology and Biomedical Imaging. In February 2017, Dr. Desikan was diagnosed with amyotrophic lateral sclerosis (ALS), also known as Lou Gehrig’s disease, one of the diseases he studies. He says that if he had had any hint that he would develop ALS, he would have done anything he could to stop or slow the progression of the disease and the effect it has had on his life.
Dr. Desikan’s story has been profiled in the Washington Post and Bostonia magazine, and on Good Morning America. He has also published op-eds in the Washington Post and the San Francisco Chronicle. In both pieces, he discusses how genetic research holds promise for neurogenerative diseases such as ALS or Alzheimer’s.
In a paper published on April 8, 2019, on JAMA, Drs. Desikan and Sugrue discuss polygenic scores—what they are and why they are important. “Using advanced computer models, scientists are adding together the influence of the hundreds, even thousands of DNA variants associated with a given disease into what is called a ‘polygenic score,’” they explain. A polygenic score is a single number that quantifies an individual’s particular genetic risk of disease. A personalized polygenic score could help someone prevent disease, live longer and plan for their future. Note—they are not diagnostic tests. They measure the risk for developing a disease. There is certainly uncertainty in polygenic scores, which leaves room for action. “If disease onset isn't solely determined by genes, then lifestyle or therapeutic interventions can prevent or modify the trajectory of disease,” they write.
Polygenic risk scores can help with the following:
- Informing treatment decisions and lifestyle modifications
- Influencing disease-screening strategies
- Planning for the future
Drs. Desikan and Sugrue say that polygenic scores will need to “undergo rigorous evaluation by the medical community before being incorporated into clinical practice.” But, this is already happening. A partnership between Dash Genomics and HealthLytix brought about a polygenic test for Alzheimer's disease available to anyone who already has their DNA data from Ancestry.com or 23andMe. They can upload their data, and for $99, an app on your smartphone can tell when someone is at their greatest risk for developing dementia.
Today, we have unprecedented access to genetic information. At UCSF, scientists are experimenting with and developing molecular pathway-specific polygenic scores. Drs. Desikan and Sugrue jointly run the Laboratory for Precision Neuroimaging at UCSF. Aware that their approach is novel and therefore considered high risk from the perspective of traditional funding mechanisms such as the NIH, they are seeking funding for this project through both traditional and novel crowdsourcing approaches. Learn more about how to donate.