The polymorphisms of DHCR7/NADSYN1 participate in susceptibility to many diseases, including deficiency of VitD, acute coronary syndrome, Alzheimer’s disease and ULs (Lu et al., 2012; Wise et al., 2014; Elbehairy et al., 2021; Liu et al., 2021). The gene discussed is DHCR7; the disease is Alzheimer disease.