Neurodevelopmental Regression, Abnormal Movements, Loss of Speech, and Seizures (NEDAMSS) is caused by changes in the IRF2BPL gene. Variants in the gene can also lead to other neurodevelopmental presentations. Due to the limited number of cases that have been described to date, clinicians may have a limited understanding of what types of symptoms can develop in affected individuals and at what age. The purpose of the study is to gather clinical information about progression, treatments and outcomes for patients with variants in IRF2BPL. The investigators will collect information about medical history, growth, development, treatments and the results of previous genetic tests. In some cases, the investigators may also collect tissue samples. This is a non-interventional study that will expand the current understanding of the range of health concerns that can be seen in individuals with changes in the IRF2BPL gene by collecting medical information and samples from a larger group of affected individuals.
