Triphalangeal Thumb with Polysyndactyly, also known as triphalangeal thumb-polysyndactyly syndrome, is related to synostosis and polydactyly, preaxial ii. An important gene associated with Triphalangeal Thumb with Polysyndactyly is LMBR1 (Limb Development Membrane Protein 1). Affiliated tissues include heart, and related phenotypes are triphalangeal thumb and finger syndactyly