The list of the prioritized candidate genes including a total of 28 genes was screened for putative pathogenic variants: the 14 genes known as the most common mutated genes (ABCA12, ALOX12B, ALOXE3, CASP14, CERS3, CYP4F22, LIPN, NIPAL4, PNPLA1, SDR9C7, SLC27A4, SULT2B1, ST14, TGM1) for about 85% of non-syndromic ARCI cases, the 8 relevant genes (ELOV4, GJA1, GJB3, GJB4, KDSR, KRT83, PERP, TRPM4) involved in the EKVP phenotypes and the 6 already known genes (ABHD5, GJB2, KRT1/KRT10, LOR, SPINK5) to be associated with the clinical differential diagnosis of EKVP (Table 1). This evidence concerns the gene CYP4F22 and erythrokeratodermia variabilis.