Part of a genetic counselor’s job is to take a family history. This record of the family’s medical history typically goes back for at least three generations. It is designed to track disease through a family, providing enough information from each generation to help determine if the disease is hereditary or just occurring by chance. Genetic counselors gather information about each individual that is affected by a particular disease, including the age of onset, their symptoms or disease progression, and their cause of death. In practice, it becomes a snapshot of the evolution of disease in a particular family.
While the coronavirus is not hereditary, meaning it cannot be passed down from one generation to the next, it still has its own genetic evolution of sorts. Highly trained immunologists that specialize in infectious disease genomics, otherwise known as “DNA sleuths”, have sequenced the genetic code of the virus in an effort to identify its origin, make note of where and how it presents, and determine if this information could be used to better contain it or develop a vaccine against it. Like genetic counselors creating a family history on the spot while they talk with their patients, because of the rapid amount of data coming out of countries worldwide, scientists are literally creating the family tree of the coronavirus in real time. This tracking is primarily occurring on an open-source website called Nextstrain that publishes “situation reports” on the virus progression.
Scientists in China sequenced the virus’s genome and made it openly available on January 10th. Repeated sequencing of the virus from cases around the world demonstrates when and how it mutated. These mutations help scientists pinpoint where the virus spread from. For example, in late February, scientists in Brazil sequenced the viral genome of their first case and compared it to sequences already posted online, mainly those from China. The first individual affected in Brazil had recently traveled to Italy, so the assumption was that he picked it up there. However, the genetic sequence from his infection connected it back to China and an outbreak in late January in Germany.
This same genomic sequencing can also be used to determine the original origin of the virus. Scientists expect that the initial virus was almost certainly one that circulates harmlessly in bats. The ancestor of 2019-nCoV likely existed in bats for some time, until a single virus developed a mutation, allowing it to jump from animal to human. Researchers tracing the virus believe this was a single introduction, meaning what is sustaining the virus now is human-to-human transmission, not infected bats.
Beyond simply identifying the origin of the virus or even how it entered a particular country, scientists hope to use this genomic tracking to identify holes in containment and to help public health officials better understand the spread of the virus. Genetic data shows that coronavirus entered Europe multiple times. While a late January outbreak in Germany was thought to have been caught early and contained, genomic data now indicates that one fourth of the world’s new infections appear to be genetically similar to the cluster in Munich. Genetics is, as it often does, telling the truth. Supposed “containment” of the virus does not eliminate the possibility of a transmission chain that can spread to create a significant downstream outbreak.
This appears to be in contrast to what happened in the state of Washington, whose known cases of the virus now top 1,000. The expectation was that there were multiple entry points for the virus in WA, like in Europe. However, when the genome of a recent case was tested and compared to the genome of the first case detected over six weeks ago, researchers found that they shared a specific mutation. This likely means the virus had been spreading, undetected, during that six weeks.
While the situation may feel dire, there are extreme benefits to the ability to track this virus effectively and efficiently. The availability of cheap, fast genomic sequencing techniques alone are a game changer when it comes to understanding how fast the virus mutates and the effects of those mutations on the symptoms of the virus. While creating a family history may feel like a passive activity, the wealth of genetic data being amassed about this virus allows scientists to quickly get to work on both a vaccine and better, more comprehensive testing.
The experience of the coronavirus has confirmed one of the hallmark truths of genetics. There is a great wealth of information in one’s family history, both for humans…and for viruses.
Jessica Greenwood is an independent consultant to Sharing Health Genes. As a licensed genetic counselor and digital health consultant, she works with health-related organizations looking to deliver memorable messages of health in the digital space. Mrs. Greenwood started her career in a clinical role, working for eight years as a preconception and prenatal genetic counselor before transitioning to industry. Mrs. Greenwood completed a year-long certificate program in Digital Health Communication at Tufts University that spearheaded her work in digital health. She now consults with health-related organizations, assisting with the creation and execution of a digital strategy including the development of health literate patient-centered educational materials. Mrs. Greenwood earned a Bachelor of Science degree from North Carolina State University with a minor in Genetics and a Master of Science in Genetic Counseling from the University of North Carolina at Greensboro.