ABHD2 and Alzheimer disease: COVID-SD (COVID-19 SD) and HS shared 12 common genes: ABHD2, CSRNP1, FKBP8, IL1RAP, KCNE3, LILRA3, MAPK14, SIGLEC10, SLC22A18, TIMP1, TMEM45B and TNFAIP6; COVID-19, SD and AD shared 3 genes: FOXO4, LCN2 and SMIM5; COVID-19, SD and EP shared 1 gene: CAPG; COVID-19, SD and PD shared 2 genes: CD19 and FOS; COVID-19, HS and PD shared 1 gene: FOSB (refer to Supplementary Table S4).