Christianson syndrome (CS) is a recently discovered X-linked neurodevelopmental disorder caused by deleterious mutations in SLC9A6 which encodes the sodium-hydrogen exchanger known as NHE6. This protein, along with 8 other NHE proteins, are members of the family of solute carriers found localized to different membranes in cells where they are thought to influence the pH of luminal areas. NHE6 is associated with early endosomes and recycling endosomes and recent studies of a knockout mouse model have shown defects in growth factor signaling, neurotransmitter receptor cycling as well as in lysosomal function. Patients with CS are clinically recognized by features of intellectual disability, ataxia, epilepsy, minimal verbal status, postnatal microcephaly, and cerebellar degeneration. Autistic features have also been ascribed to some patients. Prior to identification of the CS gene, the presence of a `happy demeanor' typically led to a diagnosis of Angelman syndrome, and thus was referred to as X-linked Angelman-like syndrome. Importantly, males with CS described to date have epilepsy, with seizure types including: infantile spasms, tonic seizures, tonic-clonic seizures, myoclonic seizures, drop seizures, and episodes described as staring spells. Clinical involvement in female carriers of CS has been less closely analyzed to date. While CS is a rare condition, Morrow and colleagues have identified 21 affected families and 26 individuals, which include families and patients from the United States, Canada, and Europe. A Christianson Syndrome Association (CSA) was formed in 2011 by a family in Houston, Texas, and a similar organization has now been established in Canada. The CSA held an initial meeting at Brown University in 2013 (hosted by Dr. Eric Morrow) that brought together families with interested clinicians and scientists. The CSA strongly supports the inclusion of an international scientific conference in conjunction with its 2015 family meeting and the purpose of this proposal is to secure funding to facilitate this event. Planned for this meeting are presentations from a diverse array of well-known speakers and CS experts - national and international, including leaders in the field of neurodevelopmental and seizure disorders. We also anticipate the creation of impactful opportunities for junior investigators, including women and minorities, to participate in scientific exchange and to meet CS patients and their families. Key outcomes expected from this meeting include: (i) networking and establishment of collaborative research and clinical outreach programs; (ii) generation of new ideas on the pathogenesis and possible treatment of CS, including new avenues of research and collaborative grants; (iii) expansion of the CS research and clinical community, including the introduction of junior scientists and clinicians to the importance of studying CS and other related rare diseases; and (iv) establishment of an international CS research and clinical network to foster fully collaborative, multi-laboratory basic research and to encourage initiation of a patien registry and natural history study in order to advance patient care and treatment.