2015). Tumor immunohistochemistry (IHC) can also support pathogenicity by demonstrating the loss of SDHA expression (Miettinen et al. 2013). However discrepancies between IHC results and predicted pathogenicity of SDH gene variants, appear to be more common for SDHA variants identified in patients with GIST (Evenepoel et al. 2015). This evidence concerns the gene SDHB and gastrointestinal stromal tumor.