Truncating mutations in the ATP-binding cassette subfamily A member 12 (ABCA12) gene tend to cause Harlequin ichthyosis (HI, OMIM #242500), while ABCA12 missense mutations are associated with lamellar ichthyosis (LI; OMIM #601277) [6,7]. Here, ABCA12 is linked to Harlequin ichthyosis.