In addition, ARCI has been classified into fifteen genetic forms based on their causative genes including PNPLA1, LIPN, CASP14, CYP4F22, ABCA12, NIPAL4, ALOXE3, SULT2B1, ABCA12, SDR9C7, CERS3, ALOX12B, ST14, TGM1 (Fachal et al., 2014), of which the underlying pathogenic gene responsible for ARCI type 7 has not been defined. The gene discussed is CYP4F22; the disease is autosomal recessive congenital ichthyosis.