Here we report the first case of molecular co-occurrence of CdLS and generalized pustular psoriasis in a patient with novel heterozygous nonsense variant in RAD21 (c.1306C>T, p.Gln436*), pathogenic for CdLS type 4, and a previously unreported truncating variant in TNFAIP3 (c.2199C>A, p.Cys733*), predicted to disrupt NF-κB regulation and classified as a variant of uncertain significance. This evidence concerns the gene RAD21 and generalized pustular psoriasis.