A Conversation with Health Content Scientist Alison Chubb

This interview is part of an occasional series of profiles introducing you to the people behind 23andMe’s content curation team. This team of 23andMe scientists has the unique job of researching, evaluating, and Alison4developing the health-related information that is reported to customers. Their rigorous process of combing through scientific literature, vetting genetic information and ensuring that published scientific findings meet our standards for inclusion, directly impacts what you see when you log into your 23andMe account. “What we currently know about the genotype-phenotype link in terms of human health and disease is only the tip of a very huge iceberg.” What were you researching before you came to 23andMe? The common thread of my academic research was using DNA sequences from different populations and different species to help understand how they are related; this field is called molecular phylogenetics. During my master’s program I used molecular phylogenies to study the population genetics of Hawaiian freshwater fishes, and during my PhD work, I studied the evolutionary relationships among modern bird lineages. Interestingly, I used similar analytical techniques to the ones we use here at 23andMe to figure out our customers’ ancestry information, but I used them for fish and birds, not humans — when it comes to DNA, the same analytical principles can apply to any group of organisms. One huge difference is that my data sets were much much smaller! Back when I started, most people were only using mitochondrial DNA sequences to build evolutionary trees of animals. I was able to amplify and sequence a nuclear gene that no one had ever tried before and showed that it, too, had utility for studying evolutionary relationships.
Alison Chubb, PhD, Health Content Scientist From: Olmsted Falls, Ohio Education: BA, English, Princeton University MS, Conservation Biology, University of Minnesota PhD, Integrative Biology, UC Berkeley Fun Fact: Alison loves bird watching and this spring had chickadees, towhees, juncos, and wrens all nesting in her backyard. She also rescued and raised a baby hummingbird for a few days before releasing it back into the wild.
Why are you excited about genetics? I’ve always wanted to delve more deeply into the genotype-phenotype link, and the advent of whole genome genotyping and sequencing has really accelerated our ability to do that as scientists, especially in the realm of health and disease. Being married to a doctor and having a child with a congenital heart defect (successfully repaired) has brought me much closer to the medical world than I ever would have expected, and has increased my curiosity about how our genes influence our own health. When I learned that 23andMe’s goal was to help elucidate and communicate the link between our health and genetics on a really huge scale, I knew it was something I wanted to be a part of.I’ve always loved reading scientific literature, but the hectic schedule of grad school doesn’t allow you time to read much outside your field. At 23andMe, I get to look at a wide breadth of literature and think about how to communicate those concepts to our customers – that’s an incredibly inspiring challenge.How do you decide what to include in 23andMe reports? In my role at 23andMe, I look at everything through the lens of clinical validation. That means that our team takes a genetic variant thought to be pathogenic (capable of causing disease) and we try to find scientific papers to support or refute that claim. In general, we look for population studies to show that a case population (with the disease) has the genetic variant far more often than the control population (without the disease), or that both the variant and the disease co-segregate, or show up together, in family-level studies.You’ll see links to scientific literature in our health reports, and our goal is that those papers show a significant effect size, are replicated, functionally relevant, and present convincing evidence that particular variants are strongly associated with particular conditions.Tell us about a recent breakthrough in technology that you think will have a big impact. Next Generation Sequencing is a breakthrough that will change the world of clinical genetics. Being able to sequence patients’ genomes faster and less expensively will hopefully accelerate diagnoses, treatments, and cures. The big challenge, of course, is parsing all that data and figuring out how to separate the wheat from the chaff in terms of variants that matter (are pathogenic) and those that don’t. Data generation is no longer the obstacle — but data analysis on a mammoth scale is.Did you learn anything interesting from your 23andMe results? Did you make any changes as a result of taking the test? One fascinating thing about the 23andMe health results (for customers who joined before November 22d, 2013) is that you can keep coming back to them again and again and learn something new. This is, in part, because your own health status, or that of a family member’s, can change over time and certain results may become more relevant.For example, when I first received my own 23andMe results I didn’t pay much attention to the fact that both my husband and I are considered “rapid metabolizers” of a particular class of drugs known as proton pump inhibitors (PPIs), which are used to reduce stomach acid. “Rapid metabolizer” just means that our bodies are likely to break down the drug fast enough so that standard doses may not always be enough to improve symptoms like heartburn or acid reflux. Neither my husband nor I have problems with stomach acid, so at the time, I didn’t give this result a second thought.Fast forward to 2014, and our son has recently developed symptoms of reflux and has been prescribed a PPI to take every day. Based on our genetic results, we know that he is also a “rapid metabolizer,” even though he doesn’t have his own 23andMe account. Consequently, we are paying close attention to whether the drug seems to be improving his symptoms or whether we should talk to the doctor about possibly adjusting the dose or switching medications. The jury is still out, but it’s great to have some extra information that can help inform our approach to this drug.What’s one thing the average consumer should know about genetics? Consumers should understand that we still know very little about the interplay of genes, lifestyle, and environment for most of the most common, serious conditions that impact us personally and as a society — diabetes, heart disease, and stroke, for example. What we currently know about the genotype-phenotype link in terms of human health and disease is only the tip of a very huge iceberg.