A novel initiation codon mutation of PAX9 in a family with oligodontia.

OBJECTIVE: Recent studies have attributed non-syndromic tooth agenesis to mutations in several genes, including MSX1, PAX9, AXIN2, WNT10A and EDA. In this study, mutation of PAX9gene was investigated in a four-generation Chinese family with oligodontia. DESIGN: Genomic DNA was isolated from the blood samples of all the available family members. Candidate genes MSX1 and PAX9 were amplified using polymerase chain reaction and then directly sequenced. RESULTS: A novel initiation codon mutation was identified; it consisted of a heterozygous c.2T>G mutation in the PAX9 gene which changed the ATG initiation codon to AGG. Restriction-enzyme analysis was performed to verify this mutation, which was segregated amongst the members with the oligodontia phenotype. CONCLUSIONS: Our results demonstrate a new initiation codon mutation in the PAX9 gene. This mutation probably caused the oligodontia in the investigated Chinese family through haplo-insufficiency.