Early-onset grade 2-3 diffuse gliomas and schwannomas increase the risk of central nervous system tumors among the patients' relatives.

The early onset of grade 2-3 diffuse gliomas is associated with an increased risk of similar tumor entities. Early-onset schwannomas dramatically increase CNS tumor risk with a broader tumor-type profile. In future studies, it would be important to identify the underlying shared hereditary factors that contribute to the development of familial diffuse gliomas.