Estimation of monoamine and cyclic-AMP turnover and amino acid concentrations of spinal fluid in autistic children.

A group of autistic children had the concentrations of spinal fluid 5-HIAA, HVA and cAMP studied before and twenty-four hours after afflux blockade with probenecid. Spinal fluid aminoacids were studied before probenecid administration and found to be normal. Three children lacked an increase in the concentration of 5-HIAA after probenecid administration, and two had only modest increases in the concentration of spinal fluid HVA. The concentration of spinal fluid cAMP was increased by probenecid administration in all eight children. These findings suggest an abnormality in monoamine metabolism in a small group of autistic children.