What causes neuroblastoma?
The causes of neuroblastoma are not precisely known. Current research holds that neuroblastomas develop when cells produced by the fetus (neuroblast cells) fail to mature into normal nerve or adrenal cells and keep growing and proliferating. Most neuroblastoma cells have genetic abnormalities involving chromosome #1, where a deletion or rearrangement is
found on the short arm of this chromosome. The chromosome abnormality, in turn, causes amplification of an oncogene called n-myc, even though this gene is not located on chromosome #1. The amplification of n-myc causes uncontrolled cell growth. A variety of other chromosome abnormalities may also be present in neuroblastoma.
It is estimated that as many as 20 percent of neuroblastoma cases result from an inherited mutation, followed by a second mutation occurring after birth, which together initiate uncontrolled cell growth. The remainder of the cases occur from two acquired mutations after birth. Because the tumor occurs very early in childhood, it is doubtful that any environmental exposures the child has incurred could be linked to the development of the tumor.
Neuroblastoma is more common in children born with fetal hydantoin syndrome, neurofibromatosis, and Beckwith-Wiedemann syndrome. The exact relationship between these conditions and the disease are not known. The chance for neuroblastoma to be present in a future sibling of the patient is about 1 percent. If more than one child has neuroblastoma, the chance for reoccurrence increases. Research is being conducted to determine if maternal exposure to any toxic substances, environmental pollutions, or radiation during pregnancy could have any link to the child developing neuroblastoma. |
