People with Prader-Willi syndrome (PWS) who had COVID-19 experienced either no symptoms or only mild illness due to the infection, an international survey study found.
These findings were unexpected, as researchers had put forward the hypothesis that the presence of other conditions typically coexisting with PWS would make symptoms of COVID-19 appear more severe.
“A possible explanation, supported by anecdotal evidence from parents and professional carers, is that people with PWS have a degree of innate immunity to viral infections,” the researchers wrote. “However, likely selection effects and a relatively low number of responses means that further evidence is needed to test this hypothesis.”
The study, “The presentation, course and outcome of COVID-19 infection in people with Prader-Willi syndrome: unexpected findings from an international survey,” was published in the Orphanet Journal of Rare Diseases.
As the COVID-19 pandemic enters its third year, scientists are still looking to determine the real impact of the virus on certain populations.
While the most common symptoms of COVID-19 are fever, cough, tiredness, and a loss of taste or smell, in older people and those who are obese or have a medical condition, the symptoms are likely to be more severe.
Children with PWS may become obsessed with food and unable to control their appetite. As they grow older, the overeating often results in a rapid gain of weight. This is linked to high rates of diabetes mellitus and breathing problems, both of which are also known risk factors for severe COVID-19 symptoms.
To determine whether COVID-19 symptoms are worse in people with PWS than in the general population, the researchers developed an online questionnaire that was promoted globally through the International Prader-Willi Syndrome Organization network.
The organization asked family members and others who cared for someone with PWS who had — or may have had — COVID-19 to complete the questionnaire, starting at the end of April 2020.
Over one year, 72 people across 17 countries turned in the questionnaire. There were 47 adults and 25 children. Their mean age was 25.6 years, ranging from 2 to 58.
Their mean body mass index (BMI), a measure of body fat based on weight and height, was 28. Based on their BMI, 16 patients were considered to be overweight and 28 were obese.
Five patients also had diabetes mellitus, which causes glucose (sugar) levels in blood to be abnormally high, and 18 had sleep apnea, which occurs when breathing slows or stops repeatedly for short periods of times during sleep.
Of the 72 patients, 61 tested positive on a test to detect the COVID-19-causing virus or antibodies against it, and five were diagnosed by a doctor. Six patients were suspected to have had COVID-19 because they had symptoms or were in contact with a confirmed case of COVID-19.
Almost 30% of the patients had no COVID-19 symptoms. For the remaining 70%, the most common symptoms were a raised temperature (fever), fatigue or daytime sleepiness, dry cough, and a sore throat.
“Daytime sleepiness is a characteristic of people with PWS and so may have been over-reported,” the researchers wrote.
Generally, the symptoms were mild and lasted less than one week. Six (8.5%) of the patients were seen in the hospital, but no one needed ventilatory support for breathing, required intensive care, or died. One patient spent four days in the hospital due to low oxygen levels and received oxygen therapy.
When the researchers watched for a possible link between symptom duration and other factors, they found it was not related to age, BMI, sex, or the type of disease-causing mutation.
The researchers hope they can use the data that emerged from this study to inform the management of future pandemics.
“Our hope is that the findings from this survey will inform the care of people with PWS in this pandemic and also our response to future similar pandemics,” they wrote in the questionnaire’s cover.
Data from another survey suggests a similar picture, in which PWS does not seem to increase the risk of severe COVID-19.