Autism is a disorder characterized by extreme withdrawal, and a severely impaired ability to interact socially. The conventional wisdom is that about one in every 1,000 children suffers from autism, but several recent studies have suggested that the incidence is much higher. Whether infants are born autistic or develop the disorder later has been hotly debated. Studies have pointed to a genetic component, but symptoms don't normally develop until age 1 or 2.

Researchers found that children with mental retardation or autism are more likely to have high levels of four particular brain chemicals that can be detected in the blood shortly after birth. The finding could help in the diagnosis and treatment of the neurological conditions, which often are not recognized until a child is several years old.

The researchers measured levels of eight brain proteins in newborn blood samples from 64 children who were later diagnosed with autism, 66 with mental retardation, 65 with cerebral palsy, and 54 healthy (control) children. They found that four of those chemicals -- vasoactive intestinal peptide (VIP), calcitonin gene-related peptide (CGRP), brain-derived neurotrophic factor (BDNF) and neurotrophin 4 (NT4) -- were elevated in children with autism or mental retardation.

Most children with autism or mental retardation had concentrations of two or more of the measured neuropeptides or neurotrophins...that exceeded the level indicated. Few children with cerebral palsy and no control child did.More research is need to determine if testing newborns could help distinguish which youngsters will go on to be diagnosed with autism or mental retardation.

American Academy of Neurology Annual Meeting in San Diego, California March 4, 2000