Tbx3 gene is a member of a phylogenetically conserved family of genes that share a common DNA binding domain, the T box. T box genes encode transcription factors involved in the regulation of developmental processes. Tbx3 is a transcriptional repressor and is thought to play a role in the anterior/posterior axis of the tetrapod forelimb. Mutations in this gene cause ulnar mammary syndrome, affecting limb, apocrine gland, tooth, hair, and genital development. Alternative splicing of this gene