AGAP3: a novel BRAF-fusion partner in pediatric pancreatic acinar cell carcinoma. AGAP3: a novel BRAF-fusion partner in pediatric pancreatic acinar cell carcinoma

Most available molecular data on pancreatic acinar cell carcinoma (PACC) are provided by studies of adult cases. BRAF, RAF1 or RET rearrangements have been described in approximately 30% of cases. To the best of our knowledge, only seven cases with molecular data have been reported in pediatric PACC. We report here the comprehensive study of a PACC from a 6-year-old patient. We detected a novel AGAP3-BRAF fusion. This result showing a BRAF rearrangement demonstrates a molecular link between adult and pediatric PACC. Moreover, it identifies AGAP3, a gene located at 7q36.1 that encodes a major component of the N-methyl-D-aspartate (NMDA) receptor signaling complex, as a new partner gene of BRAF. The variability of BRAF partners is consistent with a driver role of BRAF alterations in PACC. The identification of such alterations is noteworthy for considering the use of MEK inhibitors in metastatic cases. We did not detect associated genomic instability. The better outcome of pediatric cases might be related to their stable genomic background. Overall design: one sample: pancreatic acinar cell carcinoma