What Are the Causes of ASD?

The causes for ASD are most likely genetic. In most kids who present with a mild form of ASD, despite a very extensive workup that may include blood test, urine tests, imaging studies, and other tests, everything comes back normal. The general consensus is that ASD is a genetic disorder that sometimes can’t be identified in current genetic testing. This may never become specifically identified because ASD may represent a variety of genetic abnormalities.

Identified causes for ASD include several chromosomal abnormalities involving different “genetic sites.” Fragile-x syndrome involves the x chromosome, Angelman’s syndrome involves chromosome 15, and many other chromosomal abnormalities may present with “ASD.” Other disorders such as Touberouse sclerosis, a disorder causing skin and brain abnormalities and frequent severe epileptic seizures (chromosome 9 and 16) may present with “ASD” also. Some “metabolic disorders” such as PKU (phenylketonuria), where a substance (phenylalanine) accumulates in the brain, and other disorders of metabolism may present with ASD.

Another important condition that may cause ASD is a form of a seizure disorder or Laundau Kleffner syndrome. This disorder, also known as acquired epileptiform aphasia, is a disorder in which non convulsive seizures, which occur mainly at night, may “rob” a child from previously acquired speech. This is an important diagnosis, because some treatments may effectively help it.