CDC42 and macrothrombocytopenia-lymphedema-developmental delay-facial dysmorphism-camptodactyly syndrome: In the present study, we sought to delineate the pathogenetic basis of the macrothrombocytopenia observed in Takenouchi-Kosaki syndrome and performed a functional analysis of p.Tyr64Cys in cdc-42 using CRISPR/Cas9-mediated gene editing and Caenorhabditis elegans.