In a sub-analysis focused on age (65 years), the following SNPs were found associated with symptoms: for patients aged <65 years, IL-6 597 GA/AA (p = 0.042) and MAPK 792 AA (p = 0.013) were related with fever, CYP24A1 22776 CT/TT (p = 0.012) and VDR BsmI GA/AA (p = 0.021) with cough and, finally, CYP27B1 + 2838 TT (p = 0.025), HNF4 975 CG/GG (p = 0.044) and PXR 63396 CT/TT (p = 0.014) with dyspnoea. The gene discussed is IL6; the disease is Fever.