Developmental disabilities are caused by many different kinds of trauma to the developing brain and nervous system. In many cases it is difficult to pinpoint the exact cause of the damage or time when it occurred. Many specific agents are known to cause developmental disabilities or to be associated with an increased risk of developing a disability and these are divided into nine broad categories:
Childhood accidents (including auto accidents, falls, near drowning, burns, and child abuse).
Drug and toxic substance poisoning (including the use of alcohol, caffeine, cigarettes, and other drugs both prescription and over-the-counter, as well as “street drugs” while pregnant or through ingestion during childhood).
Genetic disorders (for example: Down syndrome, Tay-Sachs disease).
High-risk conditions in women and infants (for example: pregnant women under fifteen years of age or over thirty- five years of age, maternal epilepsy requiring certain drug therapy, maternal diabetes, maternal history of repeated abortions, fetal deaths, delivery of very large or very small infants, infectious diseases during pregnancy, etc.).
Lead poisoning (including lead from paint, lead-glazed pottery, lead water pipes, and dirt contaminated by automobile exhaust).
Metabolic disorders (for example: PKU, hypothyroidism, and galactosemia).
RH blood disease.
Intrauterine and other infectious diseases (including rubella, cytomegalovirus infection, toxoplasmosis, syphilis, herpes, and enterovirus infections).