Methods: Seven patients with syndromic and non-syndromic tooth agenesis and available family members were recruited. Written consent was obtained, and the study was approved by the Ethical Committee of the University of Tokushima. DNA was isolated from saliva samples, and all exons of MSX1 and PAX9 were first sequenced. All exons of AXIN2 and WNT10A was, then, investigated in patients presenting mutations in neither MSX1 nor PAX9. Obtained data were compared with NCBI database.
Results: Mutations were identified in four patients. In MSX1, a reported heterozygous mutation and a novel frameshift mutation were found. Both mutations are located in highly conserved domains. In PAX9, an amino acid substitution and a frameshift caused by three base deletion were identified. Both are novel mutations in the paired domain. No agenesis causing mutations in MSX1, PAX9, AXIN2 and WNT10A were found in other patients.
Conclusions: A sporadic mutation in PAX9 and three familiar forms of tooth agenesis with mutations in either PAX9 or MSX1 were identified. Further investigation about other genes is required.