CYP4F22 and autosomal recessive congenital ichthyosis: To date, mutations in eleven different genes have been found to underlie ARCI: ABCA12, ALOX12B, ALOXE3, CYP4F22, NIPAL4, TGM1 and more recently CERS3, PNPLA1, CASP14, SDR9C7 and SULT2B1 [3–8].