Genomic Data Has a Diversity Problem, But Global Efforts Are Underway to Fix It
Genomics has begun its golden age. Just 20 years ago, sequencing a single genome cost nearly $3 billion and took over a decade. Today, the same feat can be achieved for a few hundred dollars and the better part of a day . Suddenly, the prospect of sequencing not just individuals, but whole populations, has become feasible.
The genetic differences between humans may seem meager, only around 0.1 percent of the genome on average, but this variation can have profound effects on an individual's risk of disease, responsiveness to medication, and even the dosage level that would work best.
Already, initiatives like the U.K.'s 100,000 Genomes Project - now expanding to 1 million genomes - and other similarly massive sequencing projects in Iceland and the U.S., have begun collecting population-scale data in order to capture and study this variation.
The resulting data sets are immensely valuable to researchers and drug developers working to design new 'precision' medicines and diagnostics, and to gain insights that may benefit patients. Yet, because the majority of this data comes from developed countries with well-established scientific and medical infrastructure, the data collected so far is heavily biased towards Western populations with largely European ancestry.
This presents a startling and fast-emerging problem: groups that are under-represented in these datasets are likely to benefit less from the new wave of therapeutics, diagnostics, and insights, simply because they were tailored for the genetic profiles of people with European ancestry.
We may indeed be approaching a golden age of genomics-enabled precision medicine. But if the data bias persists then there is a risk, as with most golden ages throughout history, that the benefits will not be equally accessible to all, and existing inequalities will only be exacerbated.
To remedy the situation, a number of initiatives have sprung up to sequence genomes of under-represented groups, adding them to the datasets and ensuring that they too will benefit from the rapidly unfolding genomic revolution.
Global Gene Corp
The idea behind Global Gene Corp was born eight years ago in Harvard when Sumit Jamuar, co-founder and CEO, met up with his two other co-founders, both experienced geneticists, for a coffee.
"They were discussing the limitless applications of understanding your genetic code," said Jamuar, a business executive from New Delhi.
"And so, being a technology enthusiast type, I was excited and I turned to them and said hey, this is incredible! Could you sequence me and give me some insights? And they actually just turned around and said no, because it's not going to be useful for you - there's not enough reference for what a good Sumit looks like."
What started as a curiosity-driven conversation on the power of genomics ended with a commitment to tackle one of the field's biggest roadblocks - its lack of global representation.
Jamuar set out to begin with India, which has about 20 percent of the world's population, including over 4000 different ethnicities, but contributes less than 2 percent of genomic data, he told Leaps.org.
Eight years later, Global Gene Corp's sequencing initiative is well underway, and is the largest in the history of the Indian subcontinent. The program is being carried out in collaboration with biotech giant Regeneron, with support from the Indian government, local communities, and the Indian healthcare ecosystem. In August 2020, Global Gene Corp's work was recognized through the $1 million 2020 Roddenberry award for organizations that advance the vision of 'Star Trek' creator Gene Roddenberry to better humanity.
This problem has already begun to manifest itself in, for example, much higher levels of genetic misdiagnosis among non-Europeans tested for their risk of certain diseases, such as hypertrophic cardiomyopathy - an inherited disease of the heart muscle.
Global Gene Corp also focuses on developing and implementing AI and machine learning tools to make sense of the deluge of genomic data. These tools are increasingly used by both industry and academia to guide future research by identifying particularly promising or clinically interesting genetic variants. But if the underlying data is skewed European, then the effectiveness of the computational analysis - along with the future advances and avenues of research that emerge from it - will be skewed towards Europeans too.
This problem has already begun to manifest itself in, for example, much higher levels of genetic misdiagnosis among non-Europeans tested for their risk of certain diseases, such as hypertrophic cardiomyopathy - an inherited disease of the heart muscle. Most of the genetic variants used in these tests were identified as being causal for the disease from studies of European genomes. However, many of these variants differ both in their distribution and clinical significance across populations, leading to many patients of non-European ancestry receiving false-positive test results - as their benign genetic variants were misclassified as pathogenic. Had even a small number of genomes from other ethnicities been included in the initial studies, these misdiagnoses could have been avoided.
"Unless we have a data set which is unbiased and representative, we're never going to achieve the success that we want," Jamuar says.
"When Siri was first launched, she could hardly recognize an accent which was not of a certain type, so if I was trying to speak to Siri, I would have to repeat myself multiple times and try to mimic an accent which wasn't my accent so that she could understand it.
"But over time the voice recognition technology improved tremendously because the training data was expanded to include people of very diverse backgrounds and their accents, so the algorithms were trained to be able to pick that up and it dramatically improved the technology. That's the way we have to think about it - without that good-quality diverse data, we will never be able to achieve the full potential of the computational tools."
While mapping India's rich genetic diversity has been the organization's primary focus so far, they plan, in time, to expand their work to other under-represented groups in Asia, the Middle East, Africa, and Latin America.
"As other like-minded people and partners join the mission, it just accelerates the achievement of what we have set out to do, which is to map out and organize the world's genomic diversity so that we can enable high-quality life and longevity benefits for everyone, everywhere," Jamuar says.
Empowering African Genomics
Africa is the birthplace of our species, and today still retains an inordinate amount of total human genetic diversity. Groups that left Africa and went on to populate the rest of the world, some 50 to 100,000 years ago, were likely small in number and only took a fraction of the total genetic diversity with them. This ancient bottleneck means that no other group in the world can match the level of genetic diversity seen in modern African populations.
Despite Africa's central importance in understanding the history and extent of human genetic diversity, the genomics of African populations remains wildly understudied. Addressing this disparity has become a central focus of the H3Africa Consortium, an initiative formally launched in 2012 with support from the African Academy of Sciences, the U.S. National Institutes of Health, and the UK's Wellcome Trust. Today, H3Africa supports over 50 projects across the continent, on an array of different research areas in genetics relevant to the health and heredity of Africans.
"Africa is the cradle of Humankind. So what that really means is that the populations that are currently living in Africa are among some of the oldest populations on the globe, and we know that the longer populations have had to go through evolutionary phases, the more variation there is in the genomes of people who live presently," says Zane Lombard, a principal investigator at H3Africa and Associate Professor of Human Genetics at the University of the Witwatersrand in Johannesburg, South Africa.
"So for that reason, African populations carry a huge amount of genetic variation and diversity, which is pretty much uncaptured. There's still a lot to learn as far as novel variation is concerned by looking at and studying African genomes."
A recent landmark H3Africa study, led by Lombard and published in Nature in October, sequenced the genomes of over 400 African individuals from 50 ethno-linguistic groups - many of which had never been sampled before.
Despite the relatively modest number of individuals sequenced in the study, over three million previously undescribed genetic variants were found, and complex patterns of ancestral migration were uncovered.
"In some of these ethno-linguistic groups they don't have a word for DNA, so we've had to really think about how to make sure that we communicate the purposes of different studies to participants so that you have true informed consent," says Lombard.
"The objective," she explained, "was to try and fill some of the gaps for many of these populations for which we didn't have any whole genome sequences or any genetic variation data...because if we're thinking about the future of precision medicine, if the patient is a member of a specific group where we don't know a lot about the genomic variation that exists in that group, it makes it really difficult to start thinking about clinical interpretation of their data."
From H3Africa's conception, the consortium's goal has not only been to better represent Africa's staggering genetic diversity in genomic data sets, but also to build Africa's domestic genomics capabilities and empower a new generation of African researchers. By doing so, the hope is that Africans will be able to set their own genomics agenda, and leapfrog to new and better ways of doing the work.
"The training that has happened on the continent and the number of new scientists, new students, and fellows that have come through the process and are now enabled to start their own research groups, to grow their own research in their countries, to be a spokesperson for genomics research in their countries, and to build that political will to do these larger types of sequencing initiatives - that is really a significant outcome from H3Africa as well. Over and above all the science that's coming out," Lombard says.
"What has been created through H3Africa is just this locus of researchers and scientists and bioethicists who have the same goal at heart - to work towards adjusting the data bias and making sure that all global populations are represented in genomics."
A new competition by the XPRIZE Foundation is offering $101 million to researchers who discover therapies that give a boost to people aged 65-80 so their bodies perform more like when they were middle-aged.
For today’s podcast episode, I talked with Dr. Peter Diamandis, XPRIZE’s founder and executive chairman. Under Peter’s leadership, XPRIZE has launched 27 previous competitions with over $300 million in prize purses. The latest contest aims to enhance healthspan, or the period of life when older people can play with their grandkids without any restriction, disability or disease. Such breakthroughs could help prevent chronic diseases that are closely linked to aging. These illnesses are costly to manage and threaten to overwhelm the healthcare system, as the number of Americans over age 65 is rising fast.
In this competition, called XPRIZE Healthspan, multiple awards are available, depending on what’s achieved, with support from the nonprofit Hevolution Foundation and Chip Wilson, the founder of Lululemon and nonprofit SOLVE FSHD. The biggest prize, $81 million, is for improvements in cognition, muscle and immunity by 20 years. An improvement of 15 years will net $71 million, and 10 years will net $61 million.
In our conversation for this episode, Peter talks about his plans for XPRIZE Healthspan and why exponential technologies make the current era - even with all of its challenges - the most exciting time in human history. We discuss the best mental outlook that supports a person in becoming truly innovative, as well as the downsides of too much risk aversion. We talk about how to overcome the negativity bias in ourselves and in mainstream media, how Peter has shifted his own mindset to become more positive over the years, how to inspire a culture of innovation, Peter’s personal recommendations for lifestyle strategies to live longer and healthier, the innovations we can expect in various fields by 2030, the future of education and the importance of democratizing tech and innovation.
In addition to Peter’s pioneering leadership of XPRIZE, he is also the Executive Founder of Singularity University. In 2014, he was named by Fortune as one of the “World’s 50 Greatest Leaders.” As an entrepreneur, he’s started over 25 companies in the areas of health-tech, space, venture capital and education. He’s Co-founder and Vice-Chairman of two public companies, Celularity and Vaxxinity, plus being Co-founder & Chairman of Fountain Life, a fully-integrated platform delivering predictive, preventative, personalized and data-driven health. He also serves as Co-founder of BOLD Capital Partners, a venture fund with a half-billion dollars under management being invested in exponential technologies and longevity companies. Peter is a New York Times Bestselling author of four books, noted during our conversation and in the show notes of this episode. He has degrees in molecular genetics and aerospace engineering from MIT and holds an M.D. from Harvard Medical School.
- Peter Diamandis bio
- New XPRIZE Healthspan
- Peter Diamandis books
- Longevity Insider newsletter – AI identifies the news
- Peter Diamandis Longevity Handbook
- Hevolution funding for longevity
XPRIZE Founder Peter Diamandis speaks with Mehmoud Khan, CEO of Hevolution Foundation, at the launch of XPRIZE Healthspan.
From infections with no symptoms to why men are more likely to be hospitalized in the ICU and die of COVID-19, new research shows that your genes play a significant role
Early in the pandemic, genetic research focused on the virus because it was readily available. Plus, the virus contains only 30,000 bases in a dozen functional genes, so it's relatively easy and affordable to sequence. Additionally, the rapid mutation of the virus and its ability to escape antibody control fueled waves of different variants and provided a reason to follow viral genetics.
In comparison, there are many more genes of the human immune system and cellular functions that affect viral replication, with about 3.2 billion base pairs. Human studies require samples from large numbers of people, the analysis of each sample is vastly more complex, and sophisticated computer analysis often is required to make sense of the raw data. All of this takes time and large amounts of money, but important findings are beginning to emerge.
About half the people exposed to SARS-CoV-2, the virus that causes the COVID-19 disease, never develop symptoms of this disease, or their symptoms are so mild they often go unnoticed. One piece of understanding the phenomena came when researchers showed that exposure to OC43, a common coronavirus that results in symptoms of a cold, generates immune system T cells that also help protect against SARS-CoV-2.
Jill Hollenbach, an immunologist at the University of California at San Francisco, sought to identify the gene behind that immune protection. Most COVID-19 genetic studies are done with the most seriously ill patients because they are hospitalized and thus available. “But 99 percent of people who get it will never see the inside of a hospital for COVID-19,” she says. “They are home, they are not interacting with the health care system.”
Early in the pandemic, when most labs were shut down, she tapped into the National Bone Marrow Donor Program database. It contains detailed information on donor human leukocyte antigens (HLAs), key genes in the immune system that must match up between donor and recipient for successful transplants of marrow or organs. Each HLA can contain alleles, slight molecular differences in the DNA of the HLA, which can affect its function. Potential HLA combinations can number in the tens of thousands across the world, says Hollenbach, but each person has a smaller number of those possible variants.
She teamed up with the COVID-19 Citizen Science Study a smartphone-based study to track COVID-19 symptoms and outcomes, to ask persons in the bone marrow donor registry about COVID-19. The study enlisted more than 30,000 volunteers. Those volunteers already had their HLAs annotated by the registry, and 1,428 tested positive for the virus.
Analyzing five key HLAs, she found an allele in the gene HLA-B*15:01 that was significantly overrepresented in people who didn’t have any symptoms. The effect was even stronger if a person had inherited the allele from both parents; these persons were “more than eight times more likely to remain asymptomatic than persons who did not carry the genetic variant,” she says. Altogether this HLA was present in about 10 percent of the general European population but double that percentage in the asymptomatic group. Hollenbach and her colleagues were able confirm this in other different groups of patients.
What made the allele so potent against SARS-CoV-2? Part of the answer came from x-ray crystallography. A key element was the molecular shape of parts of the cold virus OC43 and SARS-CoV-2. They were virtually identical, and the allele could bind very tightly to them, present their molecular antigens to T cells, and generate an extremely potent T cell response to the viruses. And “for whatever reasons that generated a lot of memory T cells that are going to stick around for a long time,” says Hollenbach. “This T cell response is very early in infection and ramps up very quickly, even before the antibody response.”
Understanding the genetics of the immune response to SARS-CoV-2 is important because it provides clues into the conditions of T cells and antigens that support a response without any symptoms, she says. “It gives us an opportunity to think about whether this might be a vaccine design strategy.”
A researcher at the Leibniz Institute of Virology in Hamburg Germany, Guelsah Gabriel, was drawn to a question at the other end of the COVID-19 spectrum: why men more likely to be hospitalized and die from the infection. It wasn't that men were any more likely to be exposed to the virus but more likely, how their immune system reacted to it
Several studies had noted that testosterone levels were significantly lower in men hospitalized with COVID-19. And, in general, the lower the testosterone, the worse the prognosis. A year after recovery, about 30 percent of men still had lower than normal levels of testosterone, a condition known as hypogonadism. Most of the men also had elevated levels of estradiol, a female hormone (https://pubmed.ncbi.nlm.nih.gov/34402750/).
Every cell has a sex, expressing receptors for male and female hormones on their surface. Hormones docking with these receptors affect the cells' internal function and the signals they send to other cells. The number and role of these receptors varies from tissue to tissue.
Gabriel began her search by examining whole exome sequences, the protein-coding part of the genome, for key enzymes involved in the metabolism of sex hormones. The research team quickly zeroed in on CYP19A1, an enzyme that converts testosterone to estradiol. The gene that produces this enzyme has a number of different alleles, the molecular variants that affect the enzyme's rate of metabolizing the sex hormones. One genetic variant, CYP19A1 (Thr201Met), is typically found in 6.2 percent of all people, both men and women, but remarkably, they found it in 68.7 percent of men who were hospitalized with COVID-19.
Lungs are the tissue most affected in COVID-19 disease. Gabriel wondered if the virus might be affecting expression of their target gene in the lung so that it produces more of the enzyme that converts testosterone to estradiol. Studying cells in a petri dish, they saw no change in gene expression when they infected cells of lung tissue with influenza and the original SARS-CoV viruses that caused the SARS outbreak in 2002. But exposure to SARS-CoV-2, the virus responsible for COVID-19, increased gene expression up to 40-fold, Gabriel says.
Did the same thing happen in humans? Autopsy examination of patients in three different cites found that “CYP19A1 was abundantly expressed in the lungs of COVID-19 males but not those who died of other respiratory infections,” says Gabriel. This increased enzyme production led likely to higher levels of estradiol in the lungs of men, which “is highly inflammatory, damages the tissue, and can result in fibrosis or scarring that inhibits lung function and repair long after the virus itself has disappeared.” Somehow the virus had acquired the capacity to upregulate expression of CYP19A1.
Only two COVID-19 positive females showed increased expression of this gene. The menopause status of these women, or whether they were on hormone replacement therapy was not known. That could be important because female hormones have a protective effect for cardiovascular disease, which women often lose after going through menopause, especially if they don’t start hormone replacement therapy. That sex-specific protection might also extend to COVID-19 and merits further study.
The team was able to confirm their findings in golden hamsters, the animal model of choice for studying COVID-19. Testosterone levels in male animals dropped 5-fold three days after infection and began to recover as viral levels declined. CYP19A1 transcription increased up to 15-fold in the lungs of the male but not the females. The study authors wrote, “Virus replication in the male lungs was negatively associated with testosterone levels.”
The medical community studying COVID-19 has slowly come to recognize the importance of adipose tissue, or fat cells. They are known to express abundant levels of CYP19A1 and play a significant role as metabolic tissue in COVID-19. Gabriel adds, “One of the key findings of our study is that upon SARS-CoV-2 infection, the lung suddenly turns into a metabolic organ by highly expressing” CYP19A1.
She also found evidence that SARS-CoV-2 can infect the gonads of hamsters, thereby likely depressing circulating levels of sex hormones. The researchers did not have autopsy samples to confirm this in humans, but others have shown that the virus can replicate in those tissues.
A possible treatment
Back in the lab, substituting low and high doses of testosterone in SARS-COV-2 infected male hamsters had opposite effects depending on testosterone dosage used. Gabriel says that hormone levels can vary so much, depending on health status and age and even may change throughout the day, that “it probably is much better to inhibit the enzyme” produced by CYP19A1 than try to balance the hormones.
Results were better with letrozole, a drug approved to treat hypogonadism in males, which reduces estradiol levels. The drug also showed benefit in male hamsters in terms of less severe disease and faster recovery. She says more details need to be worked out in using letrozole to treat COVID-19, but they are talking with hospitals about clinical trials of the drug.
Gabriel has proposed a four hit explanation of how COVID-19 can be so deadly for men: the metabolic quartet. First is the genetic risk factor of CYP19A1 (Thr201Met), then comes SARS-CoV-2 infection that induces even greater expression of this gene and the deleterious increase of estradiol in the lung. Age-related hypogonadism and the heightened inflammation of obesity, known to affect CYP19A1 activity, are contributing factors in this deadly perfect storm of events.
Studying host genetics, says Gabriel, can reveal new mechanisms that yield promising avenues for further study. It’s also uniting different fields of science into a new, collaborative approach they’re calling “infection endocrinology,” she says.