Editor’s Note: Kent Sepkowitz is a CNN medical analyst and a physician and infection control expert at Memorial Sloan Kettering Cancer Center in New York. The views expressed in this commentary are his own. View more opinion at CNN.
A profound and unexpected disparity in Covid-19 death rates has emerged among different countries. In South Korea, Norway and Australia, for example, less than 3% of confirmed cases die, while in Belgium, Italy and the United Kingdom, the case fatality rate is as high as 14%.
The reasons for this disparity remain unclear. Theories have included differences in the quality of healthcare and its accessibility, population testing rates or age, differences in mutations of the virus, rates of concurrent conditions such as heart or lung disease and, for some countries, concerns about the inconsistent reporting of deaths.
As clinicians and epidemiologists continue to analyze the data, a new group of scientific experts with a different set of tools has begun to look into genes and whether genetic differences might protect some or endanger others.
Last week, a group of American and British researchers with a primary interest in Alzheimer’s disease published a paper suggesting a genetic basis for the differences in mortality among Covid-19 patients. Their work utilizes genetic information from about 400,000 people in the United Kingdom, all with European ancestry, to identify whether certain genes are associated with certain diseases.
The researchers noticed that dementia was an underlying condition among many patients who died from Covid-19 and decided to explore whether the same gene that made people predisposed to Alzheimer’s disease might also be associated with severe Covid-19 outcomes.
The theory is not a new one. A molecule that carries cholesterol called apolipoprotein E (APOE) has a variant, APOE4, that is seen in higher rates among Alzheimer’s patients than other APOE variants. Interestingly, the same variant also has also been linked to strong inflammatory responses. And an overwhelming inflammatory response is a hallmark of severe Covid-19.
Might the same gene be related to both clinical conditions? The researchers’ findings support the idea that there is some correlation, although the study – which found only 37 patients with the APOE4 variation – is only a preliminary observation and will require more research before any cause-and-effect can be established.
This is one of the first of many observations we should expect as scientists comb the human genome for hints as to why rates of severe disease and death vary so greatly across the world – even among countries with seemingly similar healthcare quality and availability. Another study, which hasn’t yet been peer-reviewed, found that blood type A, which, like all blood types, is genetically determined, was associated with a higher risk of respiratory failure in patients with Covid-19.
The influx of geneticists studying Covid-19 is good news; brilliant minds that examine a problem from different perspectives is our most likely way forward.
But it also highlights a new set of concerns. Finding a gene is one thing; whether that gene determines an incontrovertible cause for Covid-19 mortality is something else. A genetic predisposition can easily be mistaken as a death sentence, but in many cases, luck, exercise, and a good diet can still play a role in reducing the risk of disease. Despite this, it’s easy to imagine that the emphasis on genetics could take the heat off political leaders like President Donald Trump or Brazil’s Jair Bolsonaro, who have downplayed their responsibilities during this crisis. How convenient it would be for them to be able to suggest that a disastrously managed, highly lethal pandemic outbreak was actually nothing more than the result of the wrong genes in the wrong place at the wrong time.
Furthermore, blaming people’s genetic makeup could quickly knee-cap necessary fixes to our healthcare system and any soul-searching or examination of how things might have been done better. With this and most other healthcare calamities, the fault, dear Brutus, is not in our genes, but in ourselves – or at least in the society we have created.
We welcome the expertise of the newest scientists on the block with their swirls of DNA and brilliantly sideways views of how things happen. But even if they do find a genetic basis to explain the different rates of mortality, we must not lose sight of the fact that the government’s indifference, missteps and political calculations are responsible for the tragic deaths of more than 109,000 people in the US.
