TBX1 and cleft palate: Consistent with our findings, a study reported that TGF-β regulates collagen synthesis and degradation, thereby affecting the amount of collagen present in the mesenchyme of the embryonic palate.19 The T-box gene, TBX1, is the major candidate gene for DiGeorge syndrome (OMIM #188400) and may be responsible for several phenotypes including cleft palate, while mutations in TBX22 cause a form of X-linked cleft palate (OMIM #303400).