Two clinical subtypes of FECD (in Section 1 and Section 3) are early-onset, which is associated with Q455K and L450W mutations in the COL8A2 gene [11], and the late-onset subtypes are associated with TCF4, TCF8, SLC4A11, and COL8A2 genes [149,152]. Here, COL8A2 is linked to Fuchs endothelial corneal dystrophy.