Brain Tumors: Primary - Symptoms

Causes

Genetics

Only 5 - 10% of primary brain tumors are associated with genetic disorders. These inherited conditions and associated genes include:

• Von Recklinghausen disease, also called neurofibromatosis 1 (NF1 gene) and neurofibromatosis 2 (NF2 gene)
• Turcot syndrome (APC gene)
• Gorlin syndrome, also called basal cell nevus syndrome (PTCH gene)
• Tuberous sclerosis (TSC1 and TSC2 genes)
• Li-Fraumeni syndrome (TP53 gene)

Certain types of brain tumors are specifically linked with these genetic conditions. For example, neurofibromatosis 1 is associated with about 15% of cases of pilocytic astrocytomas, the most common type of childhood glioma.

---

---

Many different cancer-causing genes (oncogenes) are involved in cancer. Growth factors are a particularly important type of oncogene associated with brain tumors. Growth factors attach to receptors (connectors) that stimulate cell growth. Epidermal growth factor receptor (EGFR) has been shown to play a role in high-grade brain tumors such as glioblastoma multiforme. Knowing the molecular origin of a brain tumor may help determine the treatment course, both for standard chemotherapy and "targeted therapy" biologic drugs.

Most genetic abnormalities that cause brain tumors are not inherited but occur as a result of environmental or other factors that affect genetic materials (DNA) in the cells. Researchers are studying various environmental factors (such as viruses, hormones, chemicals, and radiation) that may trigger the genetic disruptions that lead to brain tumors in susceptible individuals. They are also working to identify the specific genes that are affected by these environmental triggers.

Review Date: 10/21/2010
Reviewed By: Harvey Simon, MD, Editor-in-Chief, Associate Professor of Medicine, Harvard Medical School; Physician, Massachusetts General Hospital. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.

A.D.A.M., Inc. is accredited by URAC, also known as the American Accreditation HealthCare Commission (www.urac.org).