Genetics of brain tumors

Brain tumors are among the most common forms of cancer in children and acco unt for most cancer-related deaths in this age group. The incidence of brai n tumors appears to be increasing in children, while therapeutic advances h ave been modest. Few genetic studies exist on pediatric brain tumors, in pa rt because tissue from low-grade and brain stem tumors is not readily avail able, and also because individual centers have relatively few cases. Geneti c changes in infiltrating astrocytomas involve genes in the p53 and RE path ways, and show alterations that are similar to infiltrating astrocytomas in adults. The PTC gene is mutated in a subgroup of medulloblastomas, and may lead to increased proliferation in granule cells that normally express thi s receptor. Further studies are needed to identify genetic alterations in p ilocytic and low-grade astrocytomas, which account for 40% of brain tumors in children. (C) 2000 Lippincott Williams & Wilkins, Inc.