[Biochemistry and psychophysiology of autistic syndromes]

These syndromes show a genetic disposition. Some diagnostic problems are caused by hybrids with other syndromes. Central to the pathology is the demonstration of increased serotonin uptake into platelets caused by a serum and urine peptide. Furthermore, bovine casomorphin immunoreactive peptides have been found in urine and dialysis fluid as part of a general peptiduria. Peptiduria is usually caused by defects in peptide metabolizing enzymes such as peptidases. Because of considerable heterogeneity of peptides we suspect that different sets of peptidases may be defective in different families. Increased galvanic skin conductance and poor habituation in the pure syndromes reconcile with increased metabolism in attention related brain areas. The trophic effects of exorphins may explain the varied morphological defects and the increasing frequency of epilepsy with age.