A new medication for Rett syndrome, called Daybue, was recently approved by the FDA. Since there are some clinical similarities between BPAN and Rett syndrome, including regression, seizures, intellectual disability, motor changes and certain repetitive behaviors, it is natural to wonder whether Daybue could help people with BPAN. We at OHSU continue to ask ourselves this question and are reviewing information and data that may help inform our thinking about this. It is important to understand that the common Rett gene, MECP2, and the medication in Daybue have a direct link and rationale that explain why Daybue works. This specifically relates to a protein called insulin-like growth factor 1 (IGF1) that is low in Rett syndrome and restored by Daybue. In BPAN, however, there is currently no evidence that IGF1 is reduced or plays a role in disease development. Still, it is worth exploring whether Daybue could benefit the BPAN population, starting with studies in BPAN animal or cell-based models. Even if it cannot, the lessons learned from the approaches to treating Rett syndrome, which is also X-linked, will likely be useful to BPAN investigators. For these reasons, we stay informed about Rett syndrome studies with an eye towards applications for BPAN.