Researchers say their method can trace ancestry back 100,000 years and could lay groundwork for identifying new genetic markers for diseases that could be used in clinical laboratory tests
Cheaper, faster, and more accurate genomic sequencing technologies are deepening scientific knowledge of the human genome. Now, UK researchers at the University of Oxford have used this genomic data to create the largest-ever human family tree, enabling individuals to trace their ancestry back 100,000 years. And, they say, it could lead to new methods for predicting disease.
This new database also will enable genealogists and medical laboratory scientists to track when, where, and in what populations specific genetic mutations emerged that may be involved in different diseases and health conditions.
New Genetic Markers That Could Be Used for Clinical Laboratory Testing
As this happens, it may be possible to identify new diagnostic biomarkers and genetic indicators associated with specific health conditions that could be incorporated into clinical laboratory tests and precision medicine treatments for chronic diseases.
“We have basically built a huge family tree—a genealogy for all of humanity—that models as exactly as we can the history that generated all the genetic variation we find in humans today,” said Yan Wong, DPhil, an evolutionary geneticist at the Big Data Institute (BDI) at the University of Oxford, in a news release. “This genealogy allows us to see how every person’s genetic sequence relates to every other, along all the points of the genome.”
Researchers from University of Oxford’s BDI in London, in collaboration with scientists from the Broad Institute of MIT and Harvard; Harvard University, and University of Vienna, Austria, developed algorithms for combining different databases and scaling to accommodate millions of gene sequences from both ancient and modern genomes.
“Essentially, we are reconstructing the genomes of our ancestors and using them to form a series of linked evolutionary trees that we call a ‘tree sequence,’” said geneticist Anthony Wilder Wohns, PhD (above), in the Oxford news release. Wohns, a postdoctoral researcher in statistical and population genetics at the Broad Institute, led the study. “We can then estimate when and where these ancestors lived. The power of our approach is that it makes very few assumptions about the underlying data and can also include both modern and ancient DNA samples.” The study may result in new genetic biomarkers that lead to advances in clinical laboratory diagnostics for today’s diseases. (Photo copyright: Harvard School of Engineering and Applied Sciences.)
Tracking Genetic Markers of Disease
The BDI team overcame the major obstacle to tracing the origins of human genetic diversity when they developed algorithms to handle the massive amount of data created when combining genome sequences from many different databases. In total, they compiled the genomic sequences of 3,601 modern and eight high-coverage ancient people from 215 populations in eight datasets.
The ancient genomes included three Neanderthal genomes, a Denisovan genome, and a family of four people who lived in Siberia around 4,600 years ago.
The University of Oxford researchers noted in their news release that their method could be scaled to “accommodate millions of genome sequences.”
“This structure is a lossless and compact representation of 27 million ancestral haplotype fragments and 231 million ancestral lineages linking genomes from these datasets back in time. The tree sequence also benefits from the use of an additional 3,589 ancient samples compiled from more than 100 publications to constrain and date relationships,” the researchers wrote in their published study.
Wong believes his research team has laid the groundwork for the next generation of DNA sequencing.
“As the quality of genome sequences from modern and ancient DNA samples improves, the tree will become even more accurate and we will eventually be able to generate a single, unified map that explains the descent of all the human genetic variation we see today,” he said in the news release.
Developing New Clinical Laboratory Biomarkers for Modern Diagnostics
In a video illustrating the study’s findings, evolutionary geneticist Yan Wong, DPhil, a member of the BDI team, said, “If you wanted to know why some people have some sort of medical conditions, or are more predisposed to heart attacks or, for example, are more susceptible to coronavirus, then there’s a huge amount of that described by their ancestry because they’ve inherited their DNA from other people.”
Wohns agrees that the significance of their tree-recording methods extends beyond simply a better understanding of human evolution.
“[This study] could be particularly beneficial in medical genetics, in separating out true associations between genetic regions and diseases from spurious connections arising from our shared ancestral history,” he said.
The underlying methods developed by Wohns’ team could have widespread applications in medical research and lay the groundwork for identifying genetic predictors of disease risk, including future pandemics.
Clinical laboratory scientists will also note that those genetic indicators may become new biomarkers for clinical laboratory diagnostics for all sorts of diseases currently plaguing mankind.
Clinical laboratory scientists should also know experts warn that ‘herd resistance’ is more likely than ‘herd immunity’ due to low vaccination rates in many parts of the world
Scientists estimate 73% of the US population may be immune to the SARS-CoV-2 omicron variant. Whether the nation is approaching “herd immunity” against the disease, however, remains open to debate, the Associated Press (AP) reported. These estimates are relevant to medical laboratories doing serology tests for COVID-19, as different individuals will have different immune system responses to COVID-19 infections and vaccines.
More than two years into the COVID-19 pandemic in the United States, the CDC’s COVID Data Tracker shows the number of daily cases dropped to fewer than 50,000 as of March 4, 2022, after reaching a high of 928,125 on January 3, 2022.
Meanwhile, the seven-day death rate per 100,000 people stands at 2.78. That’s significantly above the seven-day death rate reached last July of .45, but well below the 7.21 mark recorded on January 13, 2021.
“We’re clearly entering a new phase of the pandemic,” William Morice, II, MD, PhD, Department of Laboratory Medicine and Pathology at Mayo Clinic in Rochester, Minn., told KARE11, an NBC affiliate.
Is Herd Immunity Achievable?
According to the AP, an estimated 73% of the US population is likely to be immune to the Omicron variant due to vaccination or natural immunity from contracting the disease. That calculation was done for the media outlet by the Institute for Health Metrics and Evaluation (IHME) at the University of Washington in Seattle. The IHME anticipates immunity to Omicron could rise to 80% this month, as more people receive vaccination booster shots or become vaccinated.
“Herd immunity is an elusive concept and doesn’t apply to coronavirus,” he told the Associated Press (AP).
Milton maintains populations are moving toward “herd resistance,” rather than “herd immunity.” This will transform COVID-19 into a permanent fixture with seasonal outbreaks similar to influenza.
Epidemiologist, Ali Mokdad, PhD (above), Chief Strategy Officer for Population Health and Professor of Health Metrics Science at the University of Washington in Seattle, believes the US is now much better positioned to withstand the next wave of COVID-19 cases. “I am optimistic even if we have a surge in summer, cases will go up, but hospitalizations and deaths will not,” he told the Associated Press (AP). Mokdad worked on the IHME model that calculated the 73% Omicron-immunity figure for the AP. However, he recommends continued vigilance toward COVID-19. “We’ve reached a much better position for the coming months, but with waning immunity we shouldn’t take it for granted,” he added. And so, clinical laboratories can expect to continue to play a vital role in the fight against the spread of the SARS-CoV-2 coronavirus. (Photo copyright: University of Washington.)
Herd Immunity Varies, according to the WHO
Because antibodies that developed from vaccines—or natural immunity from a previous infection—diminish over time, waning protection means even those boosted or recently recovered from COVID-19 could be reinfected. In addition, vaccination rates vary widely around the world. Our World in Data estimates only 13.6% of people in low-income countries had received one dose of the COVID-19 vaccine as of March 7, 2022.
The World Health Organization (WHO) points out that herd immunity levels vary with different diseases. Herd immunity against measles requires about 95% of a population to be vaccinated, while the threshold for polio is about 80%.
“The proportion of the population that must be vaccinated against COVID-19 to begin inducing herd immunity is not known. This is an important area of research and will likely vary according to the community, the vaccine, the populations prioritized for vaccination, and other factors,” the WHO website states.
Living with COVID-19
Nonetheless, the US appears to be moving into a new “normal” phase of living with the disease.
In an interview with Reuters, US infectious disease expert Anthony Fauci, MD, Director of the National Institute of Allergy and Infectious Diseases (NIAID) acknowledged a need for returning to normal living even though portions of the population—immunocompromised individuals and the unvaccinated, including children under age five who are not eligible for vaccination—remain vulnerable to more severe COVID-19.
“The fact that the world and the United States—and particularly certain parts of the United States—are just up to here with COVID, they just really need to somehow get their life back,” Fauci said. “You don’t want to be reckless and throw everything aside, but you’ve got to start inching towards that. There’s no perfect solution to this.”
Most states have lifted coronavirus-related restrictions, including masking requirements. As COVID-19 cases drop in California, Gov. Gavin Newsom put in motion a plan called SMARTER (Shots, Masks, Awareness, Readiness, Testing, Education, and Rx) that no longer responds to COVID-19 as a crisis, but instead emphasizes prevention, surveillance, and rapid response to future variant-based surges in cases.
“We have all come to understand what was not understood at the beginning of this crisis, that there’s no ending, that there’s not a moment where we declare victory,” Newsom told USA Today.
Mayo Clinic’s Morice agrees. “It can’t be out of sight, out of mind, per se, but it at least gives us hope that we can get back to some level of normalcy here over the course of the year,” he said.
Since clinical laboratories played a critical role in assay development and COVID-19 testing, medical laboratory leaders should continue monitoring COVID-19 as it moves from pandemic to endemic status due to high vaccination rates and advances in treatment options.
The COVID-19 pandemic has raised awareness among healthcare consumers as well, about the critical role laboratory medicine plays in modern medicine and healthcare. Medical laboratory leaders and pathologists would be wise to amplify this message and stress the importance of clinical laboratory testing for many diseases and healthcare conditions.
MicroRNAs in urine could prove to be promising biomarkers in clinical laboratory tests designed to diagnose brain tumors regardless of the tumor’s size or malignancy, paving the way for early detection and treatment
Researchers at Nagoya University in Japan have developed a liquid biopsy test for brain cancer screening that, they claim, can identify brain tumors in patients with 100% sensitivity and 97% specificity, regardless of the tumor’s size or malignancy. Pathologists will be interested to learn that the research team developing this technology says it is simple and inexpensive enough to make it feasible for use in mass screening for brain tumors.
Neurologists, anatomic pathologists, and histopathologists know that brain tumors are one of the most challenging cancers to diagnose. This is partly due to the invasive nature of biopsying tissue in the brain. It’s also because—until recently—clinical laboratory tests based on liquid blood or urine biopsies were in the earliest stages of study and research and are still in development.
Thus, a non-invasive urine test with this level of accuracy that achieves clinical status would be a boon for the diagnosis of brain cancer.
Researchers at Japan’s Nagoya University believe they have developed just such a liquid biopsy test. In a recent study, they showed that microRNAs (tiny molecules of nucleic acid) in urine could be a promising biomarker for diagnosing brain tumors. Their novel microRNA-based liquid biopsy correctly identified 100% of patients with brain tumors.
Atsushi Natsume, MD, PhD (above), Associate Professor at Nagoya University, led the research team that created the simple, liquid biomarker urine test for central nervous system tumors that achieved 100% sensitivity and 97% specificity, regardless of the tumor’s size or malignancy. Such a non-invasive clinical laboratory test used clinically would be a boon to brain cancer diagnosis worldwide. (Photo copyright: Nagoya University.)
Well-fitted for Mass Screenings of Brain Cancer Patients
According to the National Cancer Institute (NCI), brain and other central nervous system (CNS) cancers represent 1.3% of all new cancer cases and have a five-year survival rate of only 32.6%.
In their published study, the Nagoya University scientists wrote, “There are no accurate mass screening methods for early detection of central nervous system (CNS) tumors. Recently, liquid biopsy has received a lot of attention for less-invasive cancer screening. Unlike other cancers, CNS tumors require efforts to find biomarkers due to the blood–brain barrier, which restricts molecular exchange between the parenchyma and blood.
“Additionally, because a satisfactory way to collect urinary biomarkers is lacking, urine-based liquid biopsy has not been fully investigated despite the fact that it has some advantages compared to blood or cerebrospinal fluid-based biopsy.
“Here, we have developed a mass-producible and sterilizable nanowire-based device that can extract urinary microRNAs efficiently. … Our findings demonstrate that urinary microRNAs extracted with the nanowire device offer a well-fitted strategy for mass screening of CNS tumors.”
The Nagoya University researchers focused on microRNA in urine as a biomarker for brain tumors because “urine can be collected easily without putting a burden on the human body,” said Atsushi Natsume, MD, PhD, Associate Professor in the Department of Neurosurgery at Nagoya University and a corresponding author of the study, in a news release.
A total of 119 urine and tumor samples were collected from patients admitted to 14 hospitals in Japan with CNS cancers between March 2017 and July 2020. The researchers used 100 urine samples from people without cancer to serve as a control for their test.
To extract the microRNA from the urine and acquire gene expression profiles, the research team designed an assembly-type microfluidic nanowire device using nanowire scaffolds containing 100 million zinc oxide nanowires. According to the scientists, the device can be sterilized and mass-produced, making it suitable for medical use. The instrument can extract a significantly greater variety and quantity of microRNAs from only a milliliter of urine compared to traditional methods, such as ultracentrifugation, the news release explained.
Simple Liquid-biopsy Test Could Save Thousands of Lives Each Year
While further studies and clinical trials will be necessary to affirm the noninvasive test’s accuracy, the Nagoya University researchers believe that, with the inclusion of additional technologies, a urine-based microRNA test could become a reliable biomarker for detecting brain tumors.
“In the future, by a combination of artificial intelligence and telemedicine, people will be able to know the presence of cancer, whereas doctors will be able to know the status of cancer patients just with a small amount of their daily urine,” Natsume said in the news release.
Biomarkers found in urine or blood samples that provide clinical laboratories with a simple, non-invasive procedure for early diagnosis of brain tumors could greatly increase the five-year survival rate for thousands of patients diagnosed with brain cancer each year. Such diagnostic technologies are also appropriate for hospitals and physicians interested in advancing patient-centered care.
Decision is part of UK effort to diagnose 75% of all cancers at stage I or stage II by 2028 and demonstrates to pathologists that the technology used in liquid biopsy tests is improving at a fast pace
Pathologists and medical laboratory scientists know that when it comes to liquid biopsy tests to detect cancer, there is plenty of both hope and hype. Nevertheless, following a successful pilot study at the Christie NHS Foundation Trust in Manchester, England, which ran from 2015-2021, the UK’s National Health Service (NHS) is pushing forward with the use of liquid biopsy tests for certain cancer patients, The Guardian reported.
NHS’ decision to roll out the widespread use of liquid biopsies—a screening tool used to search for cancer cells or pieces of DNA from tumor cells in a blood sample—across the UK is a hopeful sign that ongoing improvements in this diagnostic technology are reaching a point where it may be consistently reliable when used in clinical settings.
The national program provides personalized drug therapies based on the genetic markers found in the blood tests of cancer patients who have solid tumors and are otherwise out of treatment options. The liquid biopsy creates, in essence, a match-making service for patients and clinical trials.
Liquid Biopsy Genetic Testing for Cancer Patients
“The learnings from our original ‘Target’ study in Manchester were that genetic testing needs to be done on a large scale to identify rare genetic mutations and that broader access to medicines through clinical trials being undertaken across the country rather than just one site are required,” Matthew Krebs, PhD, Clinical Senior Lecturer in Experimental Cancer Medicine at the University of Manchester, told The Guardian.
Krebs, an honorary consultant in medical oncology at the Christie NHS Foundation Trust, led the Target National pilot study.
“This study will allow thousands of cancer patients in the UK to access genetic testing via a liquid biopsy. This will enable us to identify rare genetic mutations that in some patients could mean access to life-changing experimental medicines that can provide great treatment responses, where there are otherwise limited or no other treatment options available.”
Detecting cancers at earlier stages of disease—when treatment is more likely to result in improved survival—has become a strategic cancer planning priority in the UK, theBMJ noted.
“The NHS is committed to diagnosing 75% of all cancers at stage I or II by 2028, from around 50% currently,” the BMJ wrote. “Achieving such progress in less than a decade would be highly ambitious, even without disruption caused by the COVID-19 pandemic. In this context, considerable hope has been expressed that blood tests for circulating free DNA—sometimes known as liquid biopsy—could help achieve earlier detection of cancers.”
The Guardian noted that the UK’s initiative will use a liquid biopsy test made by Swiss-healthcare giant Roche.
“We can’t guarantee that we will find a fault in the genetic code of every cancer patient we recruit, or that if we do, there will be a suitable drug trial for them,” Matthew Krebs, PhD (above), lead scientist of the NHS’ Target National pilot study, told The Guardian. “However, as we learn more about the genetics of cancer in this study, it will help doctors and scientists develop new treatments to help people in the future. Ultimately, we hope liquid biopsy testing will be adopted into routine NHS care, but we need studies such as this to show the benefit of the test on a large scale and provide the evidence that patients can benefit from being matched to targeted medicines on the basis of the blood test.” (Photo copyright: Cancer Research UK Manchester Centre.)
In her article “The Promise of Liquid Biopsies for Cancer Diagnosis,” published in the American Journal of Managed Care (AJMC) Evidence-based Oncology, serial healthcare entrepreneur and faculty lecturer at Harvard Medical School Liz Kwo, MD, detailed the optimism surrounding the “revolutionary screening tool,” including its potential for:
identifying mechanisms of resistance to therapies,
measuring remaining disease after treatment,
assessing cancer relapse or resistance to treatment, and
eliminating risk surrounding traditional biopsies.
The AJMC article estimated the liquid biopsy market will be valued at $6 billion by 2030. However, Kwo also noted that clinical adoption of liquid biopsies in the US continues to face challenges.
Welch compared the investor hype surrounding liquid biopsies to that of the now-defunct blood testing company Theranos, which lured high-profile investors to pour millions into its unproven diagnostic technology.
“Effective cancer screening requires more than early detection. It also requires that starting therapy earlier helps people live to older ages than they would if they started treatment later,” he wrote. “If that doesn’t happen, liquid biopsies will only lead to people living longer with the knowledge they have a potentially incurable disease without extending their lives. These people would be subjected to cancer therapies and their toxicities earlier, but at a time when they would otherwise be experiencing no cancer-related signs or symptoms.”
And so, while there’s much excitement about the possibility of a minimally invasive way to detect cancer, anatomic pathology groups and clinical laboratories will have to wait and see if the hype and hope surrounding liquid biopsies is substantiated by further research.
Though the variant poses low risk thanks to modern HIV treatments, the scientists stress the importance of access to early clinical laboratory testing for at-risk individuals
With the global healthcare industry hyper focused on arrival of the next SARS-CoV-2 variant, pathologists and clinical laboratories may be relieved to learn that—though researchers in the Netherlands discovered a previously unknown “highly virulent” strain of HIV—the lead scientist of the study says there’s “no cause for alarm.”
In a news release, researchers at the University of Oxford Big Data Institute said the HIV variant got started in the Netherlands in the 1990s, spread quickly into the 2000s, and that prior to treatment, people with the new virulent subtype B (VB variant) had exceptionally high viral loads compared to people with other HIV variants.
Fortunately, the scientist also found that around 2010, thanks to antiretroviral drug therapy, the severe variant began to decline.
In an interview with NPR, Chris Wymant, PhD, the study’s lead author, said, “People with this variant have a viral load that is three to four times higher than usual for those with HIV. This characteristic means the virus progresses into serious illness twice as fast, and also makes it more contagious.”
Fortunately, he added, “Existing medications work very well to treat even very virulent variants like this one, cutting down on transmission and reducing the chance of developing severe illness.
“Nobody should be alarmed,” he continued. “It responds exactly as well to treatment as HIV normally does. There’s no need to develop special treatments for this variant.”
Wymant is senior researcher in statistical genetics and pathogen dynamics at the Big Data Institute (BDI).
Epidemiologist Chris Wymant, PhD (above), lead author of the Big Data Institute study at Oxford University, says today’s modern HIV antiretroviral drug therapies effectively treat for the “highly viral” HIV VB variant he and his team discovered. “Nobody should be alarmed,” he told NPR. “It responds exactly as well to treatment as HIV normally does.” Nevertheless, he stressed the importance of access to early clinical laboratory testing for at-risk individuals. (Photo copyright: Oxford Big Data Institute.)
In their published study, the BDI researchers reported that their analysis of genetic sequences of the VB variant suggested it “arose in the 1990s from de novo (of new) mutation, not recombination, with increased transmissibility and an unfamiliar molecular mechanism of virulence.
“By the time, they were diagnosed, these individuals were vulnerable to developing AIDS within two to three years. The virus lineage, which has apparently arisen de novo since around the millennium, shows extensive change across the genome affecting almost 300 amino acids, which makes it hard to discern the mechanism for elevated virulence,” the researchers noted.
The researchers analyzed a data set from the project BEEHIVE (Bridging the Epidemiology and Evolution of HIV in Europe and Uganda). They found 15 of 17 people positive for the VB variant residing in the Netherlands. That prompted them to focus on a cohort of more than 6,700 Dutch HIV positive people in the ATHENA (AIDS Therapy Evaluation in the Netherlands) cohort database, where they found 92 more individuals with the VB variant, bringing the total to 109.
According to a Medscape report on the study’s findings, people with the VB variant showed the following characteristics:
Double the rate of CD4-positive T-cell declines (indicator of immune system damage by HIV), compared to others with subtype-B strains.
Increased risk of infecting others with the virus based on transmissibility associated with variant branching.
Wymant says access to clinical laboratory testing is key to curtailing the number of people who contract the VB variant. “Getting people tested as soon as possible, getting them onto treatment as soon as possible, has helped reduce the numbers of this variant even though we didn’t know that it existed,” he told NPR.
The University of Oxford Big Data Institute study is another example of how constantly improving genome sequencing technology allows scientists to dig deeper into genetic material for insights that can advance the understanding of many diseases and health conditions.
This new knowledge about the human genome may lead to a new set of biomarkers and clinical laboratory tests for predisposition to this health condition
Researchers across the globe are working to understand why some people who become infected with the SARS-CoV-2 coronavirus experience loss of smell (anosmia) and taste (ageusia) often for months following recovery from COVID-19 infection.
Now, pathologists and medical laboratory managers will be interested to learn that scientists from DNA testing company 23andMe believe they have identified a genetic risk factor associated with the condition. The discovery could lead to a new set of biomarkers for predisposition to loss of taste or smell that could help experts develop improved precision medicine treatments for similar conditions.
“Early data suggests that supporting cells of the olfactory epithelium are the ones mostly being infected by the virus and presumably this leads to the death of the neurons themselves. But we don’t really know why and when that happens, and why it seems to preferentially happen in certain individuals,” he added.
To perform their study, the 23andMe researchers examined the genetic tests of 69,841 individuals who self-reported that they had received a positive COVID-19 test. 68% of those people stated that they had experienced either loss of smell or taste as part of their symptomology of the illness. All the participants in the survey reside in either the United States or the United Kingdom.
After contrasting the genetic differences between those who experienced loss of taste or smell as a symptom of COVID-19 and those who did not, the team discovered a region of the genome associated with a spot located near the UGT2A1 and UGT2A2 genes. These two genes are expressed within tissue in the nose and are involved in smell and the metabolization of odorants.
“It was this really beautiful example of science where, starting with a large body of activated research participants who have done this 23andMe test, we were able to quickly gain biological insights into this disease that would otherwise be very difficult to do,” said geneticist Adam Auton, PhD (above), Vice President, Human Genetics at 23andMe and lead author of the study, in the USA Today article. If found to be accurate, the findings could lead to clinically-useful clinical laboratory tests and to development of improved precision medicine therapies for patients who are predisposed to the condition. (Photo copyright: 23andMe.)
It’s unclear if or how UGT2A1 and UGT2A2 genes may be involved in the process that leads to loss of taste or smell, but the 23andMe researchers hypothesize the genes may play a role in the physiology of infected cells which leads to the impairments.
The team found that 72% of female respondents reported loss of taste or smell as a symptom of COVID-19, which was higher than the 61% of male respondents who reported the same symptoms. In addition, the respondents who reported loss of taste or smell were typically younger than those who did not report those symptoms and persons of East Asian or African American ancestry were significantly less likely to report those symptoms.
An earlier study, titled, “Growing Public Health Concerns of COVID-19 Chronic Olfactory Dysfunction,” which appeared in the journal JAMA Otolaryngology-Head and Neck Surgery, stated that six months after contracting COVID-19 as many as 1.6 million people in the US experienced either lingering changes to their ability to smell or a complete loss of that sense.
Helping Patients Understand Why They Were Affected
Experts believe 23andMe’s findings may help patients deal with loss of taste or smell after a COVID-19 infection and increase the chance of finding suitable treatments.
“It answers the question of ‘why me’ when it comes to taste and smell loss with COVID-19,” Danielle Reed, PhD, Associate Director, Monell Chemical Senses Center, told USA Today. “Some people have it and some do not. Inborn genetics may partially explain why.”
Earlier research suggested the loss of these senses was related to a failure to protect the sensory cells of the nose and tongue from the viral infection. But according to Reed, the 23andMe study findings suggest a different cause.
“The pathways that break down the chemicals that cause taste and smell in the first place might be over or underactive, reducing or distorting the ability to taste and smell,” she said.
The 23andMe researchers noted their study had a few limitations:
It was biased towards individuals of European ancestry and lacked a replication cohort.
It relied on self-reported cases and symptom status.
No distinction between the loss of taste or smell could be determined as they were combined in a single survey question, making it unclear whether their findings relate more strongly to one symptom or the other.
Currently, there is no clinical imperative to test people in advance to see if they have a genetic predisposition to loss of smell or taste after a COVID-19 infection.
Nevertheless, this new insight into the human genome demonstrates the ongoing pace at which researchers are teasing out useful knowledge about the functions of human DNA. That knowledge will be used to do two things: first, to develop relevant, clinically-useful clinical laboratory tests, and second, to develop therapies for treating people with these genetic predispositions should they experience negative health conditions due to those genetic sequences.
