Twins may help resolve questions regarding long COVID

Investigators have launched the Twin 360 study to examine COVID-19’s impact on twins and perhaps better understand why some people continue to experience symptoms after their initial infection, according to a press release.

“Whether or not they had a serious case of COVID-19, many patients are continuing to experience symptoms like shortness of breath, chest pain, fatigue and loss of taste and smell well after they’re infected with the virus,” F. Gerard Moeller, MD, a Twin 360 investigator and director of Virginia Commonwealth University’s C. Kenneth and Dianne Wright Center for Clinical and Translational Research, said in a press release. “And, frankly, we don’t know much about why.”

Studying twins may provide researchers with a unique opportunity to answer questions about long COVID, Judy Silberg, PhD, another project investigator who is also the scientific director of the Mid-Atlantic Twin Registry and an associate professor in the department of human and molecular genetics at Virginia Commonwealth University, told Healio Primary Care.

“The comparison of [monozygotic] and [dizygotic] twins provide estimates of genetic and environmental effect,” she said. “For example, we can study whether genetic factors for long-haul symptoms are distinct from genetic factors for typical COVID symptoms. Moreover, the study of identical twins who are discordant for COVID-19 long-haul symptoms is also a powerful way of identifying effects of the environment while controlling for genetic influence, and how these effects can lead to changes in gene expression.

Studies involving other familial relationships like mother and child, or older sister and younger sister, “have important strengths, but they cannot disentangle genes from the family [and] environment because relatives are influenced by both,” she said.

Twin 360 participants will answer questions about their health and COVID-19 experience, and some may be asked to give blood and other specimen samples, the press release said. Interested identical and fraternal twins, triplets, quadruplets and quintuplets from all ages, races and ethnicities should reach out to Virginia Commonwealth University by the end of the year if they want to take part in the study, Silberg said.

Investigators hope to publish results from Twin 360 in 2022, she added.