ABSTRACT
Inherited genetic alterations are predisposing risk factors for brain tumors (Table 1.7). These genetic alterations are usually germline mutations that increase an individual’s risk for
a specific type or types of brain tumor and other malignancies. Because each mutation is found in every cell in the body, having been transmitted through parental DNA, the resultant brain tumor usually occurs as part of a syndrome that includes systemic cancers and
other malformations as well as CNS tumors (Chapter 12). Although these syndromes account for a small minority of brain tumors (about 5% of gliomas are familial and about 1% have a possible autosomal dominant inheritance),71 the wide range of genetic abnormalities that can lead to CNS neoplasms suggests that there may be many genetic ‘avenues’ that can cause these tumors. Furthermore, the study of familial syndromes, where genetic abnormalities are more easily identified, may aid in finding similar defects in the more common sporadic brain tumors.
