What causes mental retardation?
Doctors have found many causes of mental retardation. The following are most common: Genetic conditions. Sometimes mental retardation is caused by abnormal genes inherited from parents, errors when genes combine, or other reasons. Examples of genetic conditions are Down syndrome, fragile X syndrome, and phenylketonuria (PKU). Problems during pregnancy . Mental retardation can result when a baby does not develop inside the mother properly. For example, there may be a problem with the way the baby’s cells divide as it grows.