TBX20 encodes a T-box family member. The T-box family members share a common DNA binding domain, termed the T-box, and they are transcription factors involved in the regulation of developmental processes. TBX20 is essential for heart development. Mutations in TBX20 are associated with diverse cardiac pathologies, including defects in septation, valvulogenesis and cardiomyopathy. Alternatively spliced transcript variants encoding different isoforms have been found for TBX20.