TBX18 and orofacial cleft: While rare and common variants in T-box family genes, including TBX1 (OMIM * 602054), TBX10 (OMIM * 604648) and TBX22 (OMIM * 300307), have previously been implicated in both syndromic and isolated orofacial clefts [24,26,54,55,56,57,58], the TBX18 variants have not yet been linked with the risk of these craniofacial anomalies.