Can we use genetic screening of healthy populations to save lives and prevent disease? Join the conversation.Posted on by
On January 30, 2017, CDC held a special workshop to discuss the role of public health in the implementation of genetic screening programs beyond the newborn period. The workshop brought together panelists from the worlds of medical genetics and public health practice, including cancer, birth defects, and laboratory science. Workshop presenters and a CDC panel discussed the current status of genetic screening in the United States in the newborn period and the possibility for a public health screening program beyond newborns. Newborn screening is currently the largest public health genetics program in the world. Every year, more than four million babies are screened at birth for 30 or more genetic, metabolic, and other conditions—such as phenylketonuria, sickle cell disease, and cystic fibrosis—that lead to disability, morbidity, and mortality,
With the launch of the precision medicine initiative, millions of people will have their genomes sequenced. But even before such a project leads to new discoveries, we already know that many people have genetic mutations that make them more likely to get cancer, heart disease, and other conditions. We have written about some of these conditions before, notably familial hypercholesterolemia, hereditary breast and ovarian cancer, and Lynch syndrome, which collectively affect more than two million people in the United States.
Recent studies (see examples, here and here) are showing that these conditions are more common than previously thought, may not be adequately diagnosed as part of regular healthcare, may not be associated with strong family history for these conditions, and many affected people and their at risk relatives are not undergoing recommended treatments or preventive interventions that can prevent early deaths from cancer or heart disease. In addition, disparities in implementation of existing evidence recommendations exist by race, ethnicity, and geographic location. The American College of Medical Genetics and Genomics (ACMG) has published an updated panel of 59 genes with clinically actionable mutations that they recommend be returned to people undergoing genome sequencing studies. The list of genes includes the ones for the three genetic conditions mentioned earlier, as well as several others. Mutations in the original ACMG panel of 56 genes are common in the population. A recent study shows that more than 1% of the population carry pathogenic mutations in these genes and are at increased risk of common diseases, regardless of their family history.
To be sure, while the use of genome sequencing is promising in certain clinical scenarios, such as rare diseases and cancer, we do not think that whole genome sequencing in the general population is appropriate at this time. We would not recommend its use outside research studies. We have written about this before and we do not mind repeating this opinion here. But it is also becoming clearer that as science progresses, we are discovering more opportunities for using genetic screening of healthy individuals for preventing common diseases across the lifespan, outside the newborn screening context. We encourage a much-needed dialogue to assess what, when, and how genetic screening of populations should be used to prevent disease and save lives in the not too distant future.
The January 30 workshop is part of a long-term conversation that the CDC Office of Public Health Genomics would like to initiate. We will be posting soon the presentations from our speakers and hope to continue the dialogue using responses to this post and other means. We would like to explore the role of the public health system in working with healthcare providers, payers, policy makers, and the general public to ensure that people at increased genetic risk and their relatives get appropriate counseling and life-saving interventions. Questions that need to be addressed include:
- What lessons can we learn from other population-screening programs including newborn screening programs?
- What would be the potential benefits, harms, and costs of an organized public health effort?
- What laboratory platforms should we use (e.g. sequencing the whole genome or selected genes only that we know lead to high risk of preventable conditions)?
- How can we ensure the quality and access of the testing process?
- What are the ethical, legal, social, financial, and economic implications of genetic screening outside the newborn context?
- What infrastructure is needed to implement population-based genetic screening?
Join the conversation and post your comments, suggestions and issues here.