Targeted next generation sequencing provides insight for the genetic alterations in liquid biopsy of Egyptian brain tumor patients

Background Glioblastoma (GBM) is the commonest primary malignant cerebral tumor in adults. Detection of genetic mutations in liquid biopsy is endorsed rapidly throughout several solid neoplasms but still limited in GBM. Our study provides insight for the genetic alterations in liquid biopsy of the newly diagnosed GBM patients using next generation sequencing technology together with identification of the microsatellite instability (MSI) status in those patients. Results Eighteen variants detected in 15 genes which were (4, 12 and 2) missense, coding silent and intronic mutations, respectively. The 4 substitution-missense mutations were as follows: Drug responsive TP53 (p.Pro72Arg) variant was detected in 6 patients (85.7%). KDR (p.Gln472His) variant was noted in 4 patients (57.1%) as a result of substitution at c.1416A > T. Two patients revealed KIT (p.Met541Leu) variant which result from substitution at c.1621A > C. Only one patient showed mutation in JAK3 gene which was (p.Val718Leu) variant resulting from c.2152G > C substitution. Regarding MSI status, four cases (57.1%) were MSI-Low and three cases (42.9%) were MSI-High. Conclusions This study identifies the molecular landscape and microsatellite instability alternations in Egyptian brain tumor patients, which may have an important role in improving the outcome, survival and may help in evolving a characteristic individual therapy.