Familial glioma

Glioma is the most common brain tumor, characterized by several histological and malignancy grade. The majority of gliomas are sporadic, but some familial cases have been reported ( < 5%). Despite hereditary predisposition to gliomas has been associated to rare inherited cancer syndromes, such as Li-Fraumeni and Turcot's syndromes, neurofibromatosis and tuberous sclerosis, not all familial gliomas can be explained by these syndromes. Most familial gliomas seem to be characterized by cluster of two cases, suggesting the involvment of low penetrance factor risks. Moreover, no sex-linked disorders or SNPs on the X chromosome have been associated with increased glioma risk, except for ATRX gene, whose loss-of-function has been observed in 20 % of adult oligodendrogliomas and in 80 % of grade 2 and 3 astrocytomas. Finally, the risk to inherit tumors such as glioma could also be related to combinations of multiple risk variants: besides GWAS analysis identified many SNPs involved in familial gliomas at 5p15.33 (TERT), 7p11.2 (EGFR), 8q24.21 (CCDC26), 9p21.3 (CDKN2A/CDKN2B), 11q23.3 (PHLDB1) and 20q13.33 (RTEL1), mutatio could be associated with the risk of glioma ns in POT1 gene and rare variants in SPAG9 and RUNDC1 genes could be associated with the risk of glioma.