What Causes Intellectual Disability?

Doctors have found many causes of intellectual disability. The most common are:

Genetic Conditions Sometimes intellectual disability 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 Intellectual disability can result when the 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. A woman who drinks alcohol or gets an infection like rubella during pregnancy may also have a baby with an intellectual disability.
Problems at Birth If a baby has problems during labour and birth, such as not getting enough oxygen, he or she may have an intellectual disability.
Health Problems Diseases like whooping cough, the measles, or meningitis can cause intellectual disability. Intellectual disability can also be caused by extreme malnutrition (not eating right), not getting enough medical care, or by being exposed to poisons like lead or mercury. Genetic Conditions Problems During Pregnancy Problems at Birth Health Problems