HTRA4 and age-related macular degeneration: Interestingly, genes adjacent to ADAM9 on chromosome 8 (Figure 1C) display a degree of paralogy with the locus on chromosome 10 implicated in AMD,26,27 the functional variant of which is still debated.28–32 The TACC2 (MIM ∗605302), PLEKHA1 (MIM ∗607772), and HTRA1 (MIM ∗602194) genes at the AMD-associated locus on chromosome 10 have paralogs in the form of the TACC1 (MIM ∗605301), PLEKHA2 (MIM ∗607773), and HTRA4 (MIM ∗610700) genes adjacent to ADAM9 at the CORD9 locus on chromosome 8.