What causes Wilms tumor?
Researchers are learning more about how changes in the genes and other factors work to cause Wilms tumors and other cancers. They don’t know exactly why some children get Wilms tumors, but they have made great progress in learning what happens as the kidneys form in a baby. When this process goes wrong, Wilms tumor can be the result. The kidneys develop very early as babies grow in the womb. Sometimes a mistake happens as the kidney grows. Some of the cells don’t mature. Instead, they stay like early (fetal) cells. Small or large clusters of these early kidney cells can still be there after the baby is born. Most often, these cells will mature by the time the child is 3 or 4 years old. But if this doesn’t happen, the cells may begin to grow out of control. The result could be a Wilms tumor.
