RHOBTB2 and Neurodevelopmental delay: Before 2018, the role of RHOBTB2 in neurodevelopment had not been studied in detail, however since then, small case studies with one (21), two (22–25), or three patients (26), as well as larger case studies with ten or more patients (19, 20, 27) have been published on NDD related to variants in RHOBTB2. Twenty-eight different variants have been identified to cause RHOBTB2-related NDD (Figure 2) (19–27).