Researchers at Baylor College of Medicine & Texas Children’s Hospital in Houston, Texas are conducting research on TANGO2-related disease. The purpose of this study is to gather medical information to develop patient registry and to collect biological samples on children/parents for future studies. The researchers are requesting medical history and family history from the participating families. Diagnostic studies such as electrocardiograms, electrophysiology studies, echocardiograms, cardiac catheterization records and prior testing for genetic conditions will be requested. Parents will be asked to sign medical release to access prior hospitalization records. If skin fibroblast cell line has been established previously in children in clinical/research labs, parents will be asked to provide medical release to obtain these cell lines as well.