This registry was created to develop a comprehensive data-bank of individuals with creatine deficiency syndromes (CDS). This registry will allow patients, family members and researchers to gather information in a safe, confidential, online database. It will collect critical information to understand the history and progression of CDS, to make it easier for researchers to study, for patients and families to learn about treatments and for advocates to speak on behalf of the CDS community. This registry will ultimately grow the knowledge base that will build better lives for everyone with CDS.