A global team of scientists has discovered a genetic variant in the Inuit that may be responsible for the worse results of viral infections.
People with a genetic deficiency fail to produce certain types of interferons, which are proteins that fight infection. This can lead to serious illness when you come across certain viruses, such as measles, flu or COVID-19.
“If you have this option, you will have a problem with viruses,” said Trine Mogensen, a biomedical researcher at the Danish University of Aarhus and lead author of the study. published in the Journal of Experimental Medicine.
“It’s a significant risk factor.”
The findings are the result of a global network of researchers who studied the cases of five Inuit children from Canada, Greenland and Alaska who were hospitalized with unusually severe viral infections.
View from Ilulissat, Greenland. Researchers estimate that approximately 1 in 1,500 Inuit is affected by the variant, based on samples from more than 4,600 Greenlanders and just over 100 Inuit from 10 communities in Nunavik. (Getty Images)
In two of the cases, children with a history of unpleasant infections were hospitalized with severe colds. But doctors have found that few treatments are effective, and usually harmless childhood vaccines seem to make matters worse.
As their condition worsened, doctors found that they tested positive for more than one viral infection, from Epstein-Barr to chickenpox.
Two other cases involved children who developed a fever and seizures within a few weeks of receiving a common childhood vaccine against measles, mumps and rubella (MMR), which contains a weakened version of the virus. While both were recovering, one later died of COVID-19 infection – very uncommon in young children. The nurse of one of these patients was also severely ill with the flu, although she was able to receive the MMR vaccine without incident.
Researchers suspect that there may be a basic genetic explanation for why these children have suffered such unusually severe reactions to common childhood viruses. When the children were tested, they found a previously undocumented genetic variant, which meant that these children were less prepared to fight infectious diseases.
1 in 1,500 Inuit are affected
Researchers then searched a database of more than 4,600 Greenlanders and just over 100 Inuit from 10 communities in Nunavik to see how common genetic deficiency is.
They estimate that approximately one in 1,500 Inuit is affected, putting them at risk for severe reactions to COVID-19, the flu and some common childhood vaccines because they cannot fight many viruses.
By comparison, the gene is virtually non-existent in other populations. The authors say more Inuit tests need to be done to determine exactly how much may be affected.
Michael Patterson, Nunavut’s chief medical officer, questioned the newspaper’s figures, saying the study did not provide enough data to form a “firm or reliable assessment”. He said more genetic testing was needed among Canadian Inuit to say whether “it is appropriate to start screening for this condition.”
Dr Michael Patterson, Nunavut’s chief public health officer, said the figures presented in the study suggested that the option would affect “one child every two years or so” in Nunavut. (Emma Tranter / Canadian Press)
But other experts say the discovery is not surprising.
“I was not surprised,” said Shirley Tagalik, chairman of the Aqqiumavvik Wellness Society in Arviat, Nunavut, and a longtime community researcher on Inuit health. “We have known for several years that Inuit children may react differently to different vaccines.
Anna Banerjee, an expert on indigenous health, pediatrics and infectious diseases at the University of Toronto’s Dala Lana School of Public Health, was also not surprised. She has studied respiratory infections in Inuit babies for decades and has found that they occur almost four times more often than in non-Inuiteven when environmental factors are controlled.
“I have always believed that there is a genetic component,” she said.
Shirley Tagalik, a longtime community health researcher and chairman of the Aqqiumavvik Wellness Society in Arviat, Nunavut, with her granddaughter Kaviadyuk. Tagalik says the results of the study are not surprising, as she knows that Inuit children react differently to different vaccines. (Submitted by Shirley Tagalik)
Researchers emphasize that this should not lead to hesitation in the vaccine
One in 1,500 sounds like many people, but among the relatively small Inuit population, this affects about 100 Inuit people worldwide and about 50 in Canada.
For this handful of people, a flu or COVID-19 infection is likely to result in hospitalization or death. They are also at serious risk from what are known as live virus vaccines, such as MMR and yellow fever, which use a weakened form of a specific virus to teach the body’s immune system how to react when confronted with the real thing. .
But experts emphasize that the results should not make people worried about vaccines in general. First, many modern vaccines, such as the COVID-19 vaccine, do not carry the live virus at all and do not pose a risk to those with the genetic variant.
The study, conducted by a global team led by Prof. Trine Mogensen of the University of Aarhus in Denmark, found a genetic variant in some Inuit that makes it difficult to fight viruses and certain childhood vaccines containing live virus. (Submitted by Trine Mogensen)
“All other vaccinations in the children’s program, influenza and COVID-19 are still safe for those with the gene to receive,” Mogensen said.
Second, for those without the option – including most Inuit – it is vital that live virus vaccinations continue. Immunizations in children, such as the MMR vaccine, have helped reduce the severity of the disease in the north, which survived devastating outbreaks of measles and tuberculosis just a generation ago.
“Some communities have disappeared because of these viruses,” Banerjee said. “The worst thing we can say is that we should not vaccinate Inuit babies because of this risk.
Patterson encouraged parents to stick to a routine vaccination schedule and stressed that even if the newspaper’s population estimates were used, only approximately “one child every two years” would be affected.
“Avoiding vaccines would therefore significantly increase the risk of severe infection for most people.”
Dr Anna Banerjee, who studies local health, pediatrics and infectious diseases at Dala Lana School of Public Health at the University of Toronto, says it has long been suspected that genetics play a role in Inuit children’s susceptibility to infections. (Michael Cooper / University of Toronto)
Screening is possible, but far away
As with many genetic diseases, it is possible to screen for a deficiency before even having a child, or along with tests for other diseases, such as cystic fibrosis, after the child is born.
Mogensen says children who are found to be positive for the deficiency can be given a course of antiviral drugs to protect them from the worst childhood infections. She is work with pediatricians in Denmark to apply one there as soon as possible.
But Patterson said it was impossible to say when the Inuit in Nunavut could start being screened for deficits.
At present, newborn babies in Nunavut are automatically screened for various genetic diseases, which are rare, though rare, in both Inuit and non-Inuit. But labs that test for these disorders “may or may not easily test for it,” Patterson said.
Mogensen and independent genetic testing laboratories contacted by CBC suggest otherwise. Aaron Goldman, chief research officer at DNLabs Canada, said it would cost “several thousand dollars maximum” for a redesign of the test and about $ 100 for a sample thereafter. Against the background of the cost of medical care and hospitalizations, Mogensen called screening “cost-effective.”
An Inupiat mother carries her baby to Shishmaref, Alaska. (Gabriel Boyce / AFP via Getty Images)
Banerjee suggested there was a “lack of political will” to deal with something that affected a small local population.
“There is a systematic bias against the indigenous population,” she said. “We are ready to find genetic tests for rare diseases where there is more lobby.”
Tagalik, a community health researcher at Arviat, said the document represents a “minefield” for health authorities. Implementing a screening program, or even just collecting more data, would require “involvement, commitment and consent not only from the people at the top and the people below, but from all those people in between.”
In the past, she has seen her own recommendations on children’s health, blocked by government protests over spending, community leadership turnover and objections from the health facility.
“Nothing will move forward if you don’t have the government behind you,” she said, “and even if you have the government behind you, that’s not enough.”
Unique among the Inuit
Although the gene variant known as IFNAR2 deficiency has been documented only in Inuit, researchers have also found a similar variant affecting the IFNAR1 gene, in the Western Polynesians in a parallel study.
Researchers attribute this to the relatively isolated existence of these communities throughout much of their history. This may also be the reason why outbreaks of infectious diseases such as measles and tuberculosis have been so devastating to these communities.
“We believe that some of these severe infections, which were thought to be meningitis or tuberculosis, could be due to this defect,” Mogensen said.
Inuit are not often the subject of genetic research, in part because human genome mapping projects have historically focused on Caucasian populations.
A group of young Inuit children play with a puppy in Gjoa Haven, Nunavut, in 2013 (Sean Kilpatrick / The Canadian Press)
“We have a biased genome map,” Mogensen said. We have been sequencing genes for not more than 20 years and most of … patients are ……
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