DNA repair genes
DNA repair genes code for proteins that repair DNA when it is copied incorrectly. These proteins, therefore, can fix errors in the gene’s instructions which could cause cancer. Mutations in these DNA-repair genes can impair their ability to prevent cancer-causing mutations. We have two copies of most of our genes, one copy from our mother and the other from our father; therefore it is possible to inherit a gene that increases our risk of cancer. Often, if we inherit a cancer gene from one parent, the good gene from the other parent is enough to prevent it from having a harmful effect. That protection can be lost if a mutation affects the good gene. In other cases, the effect of cancer gene cannot be overridden by the matching gene from the other parent. People who inherit these kinds of genetic changes often develop a syndrome in causes a number of abnormalities. Such inherited syndromes, however, are rare, and in most cases people diagnosed with primary brain tumors do not have one of these syndromes. There are some brain tumors that are caused by genetic changes that are inherited. Patients with these tumors usually have a specific syndrome that includes a number of inherited abnormalities in addition to a higher risk of developing a brain tumor. However, these inherited syndromes are rare, and in most cases, brain tumor patients do not have one of these inherited genetic syndromes.
- Neurofibromatosis type 1 or 2.
- Von Hippel-Lindau disease.
- Tuberous sclerosis.
- Li-Fraumeni syndrome.
- Turcot syndrome type 1 and type 2.
- Klinefelter syndrome.
- Nevoid basal cell carcinoma syndrome.
- Gorlin (basal cell nevus syndrome).
- Multiple endocrine neoplasia (Werner syndrome).
Exposure to high-dose radiation, such as might be given as part of a cancer treatment, has been shown to increase the risk of developing brain tumors and some evidence that exposure to the chemical vinyl chloride poses a risk. Viral infections have been linked some rare forms of brain cancer. However, in many cases the causes of brain tumors are still not known.