Unveiling the link between genetic alterations in gamma secretase and BCMA surface density in multiple myeloma.

Cattaneo et al. report a unique case of a multiple myeloma patient with elevated B-cell maturation antigen (BCMA) surface density, potentially due to genetic alterations in the gamma-secretase protease complex-responsible for BCMA cleavage from plasma cells. No mutations in the BCMA gene were detected, but there was partial deletion of PSEN1 and amplification of PSEN2 (components of the gamma-secretase complex), which may explain the lack of response to the gamma-secretase inhibitor DAPT. This case, along with recent published literature, underscores the significance of gamma secretase in modulating BCMA density and the potential impact of its genetic alterations. Commentary on: Cattaneo et al. Genetic defects of gamma-secretase genes in a multiple myeloma patient with high and dysregulated BCMA surface density: A case report. Br J Haematol 2024;204:571-575.