RESUMO
<p><b>OBJECTIVE</b>To investigate the presence of mutation or polymorphism of ameloblastin (AMBN) gene in ameloblastomas.</p><p><b>METHODS</b>Genomic DNA was extracted from frozen tissues of 10 ameloblastomas and one malignant ameloblastoma. AMBN gene alterations were detected by PCR-direct sequencing. Restriction fragment length polymorphism (RFLP) analysis was used to further determine the nature of the changes in AMBN detected in tumor samples in comparison to 100 control samples.</p><p><b>RESULTS</b>AMBN mutation was not identified in all 11 tumor samples. The 7 types of AMBN gene alteration identified in 9 cases were proven to be polymorphisms, three of which were not previously reported. The frequency of genotype and allele of the three SNPs complied with the Hardy-Weinberg equilibrium. Neither genotype nor allele frequency showed a significant association with ameloblastoms.</p><p><b>CONCLUSIONS</b>AMBN gene mutation is not identified in the present group of ameloblastomas. The frequently detected AMBN alterations in ameloblastomas are polymorphisms, which appear to be unrelated to the occurrence of ameloblastomas.</p>