BRAF and RAS mutations in Vietnamese patients with ameloblastoma.

backgroundAmeloblastoma is a benign but locally aggressive odontogenic tumor. Genetic mutations in the mitogen-activated protein kinase (MAPK) signaling pathway, particularly those in BRAF and RAS, have been increasingly implicated in its pathogenesis, but remain underreported in Vietnamese patients.

methodsNinety-six formalin-fixed paraffin-embedded (FFPE) ameloblastoma samples from Vietnamese patients were retrospectively analyzed. Targeted exons of BRAF and RAS genes were amplified by PCR and sequenced using Sanger sequencing on an ABI 3500 Genetic Analyzer. Mutation frequencies, the prevalence of the BRAF p.Val600Glu (BRAFV600E), and their associations with clinical, radiographic, and histopathological features were evaluated.

resultsMAPK pathway mutations were identified in 63.5% of cases. BRAFV600E was the most frequent alteration, detected in 52.1% (50/96) of tumors. BRAFV600E mutations were significantly associated with radiographic radiolucent patterns, and were more common in female than in male patients (p < 0.05). In addition, a rare HRAS variant, c.22G > A (p.Val8Met) (HRASV8M), was identified. To our knowledge, this variant has not been previously reported in ameloblastoma or in public mutation databases and is therefore considered a novel, exploratory finding.

conclusionsBRAF and RAS mutations were identified in Vietnamese patients with ameloblastoma, with BRAFV600E mutation accounting for more than half of the cases. The significant association of BRAF p.Val600Glu with distinct radiographic features and female gender supports its potential value as a biomarker. In addition, the identification of a novel HRAS mutation warrants the need for further investigation.