A Study of Participants with Β-Thalassemia Treated with Betibeglogene Autotemcel

Inclusion Criteria: * Participant must be treated with beti-cel in the post marketing setting at a center in the US that participates in the Registry. * Participant must sign an informed consent and/or assent prior to enrollment as required under applicable laws and regulations. * Participant must have signed an informed consent and/or assent permitting data to be shared with Center for International Blood and Marrow Transplant Research (CIBMTR). * Participant must be followed by a hematologist based in the US. Exclusion Criteria: \- There are no exclusion criteria for Registry participation.