The registry app for children and adolescents with alpha-1 antitrypsin deficiency (AATM) enables registry participation with as little effort as possible. The focus of the registry is data collection on topics such as patients' previous medical history, current medical care, family education, severity of liver disease and much more. On the one hand, this is intended to improve the direct medical care of patients, and on the other hand, we hope to gain important insights into the course of the disease that can help better predict the severity of the liver disease. The data is stored securely on servers at the University Hospital of Bonn. Detailed information documents will be sent by post after the first registration. All further steps are possible via the app itself. In addition to register participation, the app also offers general information about the disease as well as the possibility of having previously reported laboratory data clearly displayed.