Exploring the Influence of Genetic Variants , , and on COVID-19 Severity and Long-COVID-19 Symptoms.

There is increasing evidence regarding the importance of vitamin D in the prognosis of coronavirus disease 2019 (COVID-19). Genetic variants in the vitamin D receptor () gene affect the response to vitamin D and have been linked to various diseases. This study investigated the associations of the major genetic variants , , and with the severity and long post-infection symptoms of COVID-19. In total, 100 Jordanian patients with confirmed COVID-19 were genotyped for the , , and variants using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. COVID-19 severity, the most commonly reported long-COVID-19 symptoms that lasted for >4 weeks from the onset of infection, and other variables were analyzed according to genetic variants. In this study, and polymorphisms showed no significant associations with COVID-19 severity ( > 0.05). However, a significant association was detected between the polymorphism and the severity of symptoms after infection with the SARS-CoV-2 virus ( = 0.04). The wild-type genotype was typically present in patients with mild illness, whereas the heterozygous genotype was present in asymptomatic patients. With regard to long-COVID-19 symptoms, the heterozygous and wild-type genotypes were significantly associated with persistent fatigue and muscle pain after COVID-19 ( ˂ 0.05). Most carriers of the heterozygous genotype and carriers of the wild-type genotype reported experiencing fatigue and muscle pain that lasted for more than 1 month after the onset of COVID-19. Furthermore, the genotype was associated with persistent shortness of breath after COVID-19 ( = 0.003). Shortness of breath was more common among individuals with homozygous genotype than among individuals with the wild-type or heterozygous genotype. is a possible genetic variant related to both COVID-19 severity and long-COVID-19 symptoms among Jordanian individuals. The associations between polymorphisms and long-COVID-19 symptoms should be investigated in larger and more diverse ethnic populations.