Xeroderma pigmentosum (XP) is a rare autosomal recessive disorder caused by changes in the DNA repair pathway related to variants in eight genes, and it is clinically recognized as XPA, XPB, XPC, XPD, XPE, XPF, XPG, and XPV (Digiovanna & Kraemer, 2012; Fassihi, 2013; Gruener & Morley, 2018). The gene discussed is XPA; the disease is xeroderma pigmentosum.