Genetic causes of glioma: new leads in the labyrinth

A small percentage of gliomas are caused by inheritance in cancer syndromes but there is also a general familial aggregation of glioma. Recently, low penetrant genes associated with glioma risk have been identified.

Seven independent chromosomal loci have robustly been associated with glioma risk: 5p15.33 (rs2736100, TERT), 8q24.21 (rs4295627, CCDC26), 9p21.3 (rs4977756, CDKN2A-CDKN2B), 20q13.33 (rs6010620, RTEL1), and 11q23.3 (rs498872, PHLDB1), and two loci at 7p11.2 (rs11979158 and rs2252586, EGFR). Several of these genes are obvious candidates in their role for chromosomal integrity and glioma progression. Moreover, all loci but the EGFR and CDKN2A genes display a pattern of association to certain glioma subtypes.

The causes of glioma have until recently been unknown for most cases, partly due to lack of statistically powered studies enabling subclassification of glioma subtypes. The novel chromosomal loci associated with different glioma subtypes have provided us with an additional understanding of causes of glioma. All low penetrant genes contribute with a modest increased risk and cannot by themselves be used for risk prediction. Nevertheless, they could provide a tool to understand the underlying biology of glioma progression and to be used in future studies of gene-environment studies of specific glioma subtypes.