The most important BRAF mutation in brain cancer leads to increased kinase activity, the p. V600E mutation. CTNNB1: 5 Assays The most frequently detected CTNNB1/beta-catenin mutations result in abnormal signaling in the WNT signaling pathway. The mutated codons are mainly several serine/threonine residues targeted for phosphorylation by GSK-3beta. EGFR: 4 Assays The most frequently identified EGFR mutations include P-loop and activation loop point mutations, kinase domain deletions, and insertion mutations. IDH1: 5 Assays Most of these mutations abolish magnesium binding and alters the enzyme's activity to convert alpha-ketoglutarate into R(-)-2-hydroxyglutarate instead of isocitrate into alpha-ketoglutarate. IDH2: 3 Assays These mutations all lie in the substrate binding domain, and one (p.R140Q) is associated with D-2-hydroxyglutaric aciduria. KRAS: 2 Assays The mutation assays include the most frequently occurring mutations in KRAS codons 12, 13, and 61. Mutations at these positions result in reduced intrinsic GTPase activity and/or cause KRAS to become unresponsive to RasGAP. NF2: 1 Assay NF2 is similar to some members of the ERM (ezrin, radixin, moesin) family of proteins and links cell-surface proteins with cytoskeletal components and proteins involved in cytoskeletal dynamics. Mutations in this gene are associated with neurofibromatosis type II which is characterized by nervous system and skin tumors and ocular abnormalities. NRAS: 1 Assay The most important NRAS mutation in brain cancer occurs at codon 61. PIK3CA: 3 Assays The most frequently occurring PIK3CA mutations mainly belong to two classes: gain-of-function kinase domain activating mutations and helical domain mutations that mimic activation by growth factors. PTEN: 12 Assays The most commonly detected PTEN loss-of-function mutations are due to either truncation (p.R233* and p.R130*) or point mutations causing phosphatase inactivation (p.R130 and p.R173 mutations). View a table of the mutations, associated COSMIC IDs and assay numbers, by clicking “Mutation Table” above on the right. |