Another example is two families F7810 and F9597, where we identified a homozygous founder LOF variant in RHOBTB2 leading to a RHOBTB2-related neurodevelopmental disorder characterized by global developmental delay, mild facial dysmorphism, normal brain MRI and no epilepsy in stark contrast to the RHOBTB2-related developmental and epileptic encephalopathy caused by de novo gain of function variants. This evidence concerns the gene RHOBTB2 and epilepsy.