ARCI is caused by biallelic mutations in several genes: ABCA12, ALOX12B, ALOXE3, CERS3, CYP4F22, NIPAL4, PNPLA1, SDR9C7, SULT2B1, and TGM1. Here, PNPLA1 is linked to autosomal recessive congenital ichthyosis.