Noteworthy, in a single patient with the same p.Tyr64Cys variant, localized in the switch II domain of the CDC42 gene, affecting Cdc42 binding to multiple effectors and regulators, and causing TKS (Martinelli et al., 2018), immune dysregulation with autoinflammation was observable. Here, CDC42 is linked to macrothrombocytopenia-lymphedema-developmental delay-facial dysmorphism-camptodactyly syndrome.