East Asians more likely to carry a gene variant associated with long COVID but ...

According to a preprint research article Genome-wide Association Study of Long COVID, "[t]he allele frequency of rs9367106-C at the FOXP4 locus varied greatly among the different study populations, with frequencies ranging from 1.6% in studies with non-Finnish Europeans to higher frequencies such as 7.1% in Finnish, 19% in admixed Americans, and 36% in East Asians". In other words, non-Finnish Europeans have a 1.6% chance to have this gene variant associated with an increased risk of Long COVID and East Asians have a 36% chance. This is clear enough. But some people misread these simple numbers. One journalist's article LONG COVID GENE FOUND says that "[t]he Long Covid FOXP4 mutations are 7x more common in Finnish people than in non-Finnish Europeans, and 36x more common in East Asians". The author must be interpreting the ratios in the research paper as a number (numerator) over some unit denominator. But if we do care about an inter-race comparison, we ought to say that the mutations are 7.1/1.6=4.44 times more common among the Finnish people than non-Finnish Europeans, not 7 times more. Likewise, East Asians are 36/1.6=22.5 times, not 36 times, more likely than the non-Finnish Europeans to have this mutation.

When that journalist's English article was translated into Chinese and posted to Weibo, the Chinese Twitter-like social media network, an even worse headline was added, "东亚人患新冠长期后遗症的概率是欧洲人的36倍" (East Asians are 36 times more likely than Europeans to suffer from Long COVID), naively equating the ratio of carrying a gene variant to the ratio of getting the disease, a mistake I pointed out in my Weibo posting (along with the Chinese translation). If the doctor of Angelina Jolie, the actress who opted for mastectomy to forestall a possible breast cancer, had told her she would definitely get breast cancer because she carries that gene, he could be instantly famous among the cancer researchers world wide, as a laughing stock.

So, what is the chance of getting long COVID for each race? According to a February 14, 2023 article summarizing data from the US census, Asian Americans are the least likely to get long COVID among the five race categories. However, Asian Americans with long COVID have the highest chance to experience severe symptoms. To put simply, Asian Americans don't easily get long COVID, but if they do get it, their symptoms are very serious, relative to any other race. It would be interesting to reconcile this data with the latest research about the gene variant. It's possible that Asian Americans, the relatively well-educated and well-off group of Americans, follow common hygiene practices better than other Americans, hence lower rate of COVID and therefore long COVID. But due to the FOXP4 gene variant which many East Asians carry, long COVID causes the most severe symptoms to East Asians. There are still missing links in this logic, though. For example, Asian Americans are not necessarily East Asian Americans.