The yield of laboratory investigations in children with infantile autism

Purpose: To evaluate the yield of laboratory investigations in infantile autism. Methods: We retrieved and evaluated the results of investigative procedures recorded in the medical files of autistic infants in four child developmental centers and two pediatric psychiatric outpatient clinics. Results: One-hundred and thirty-two infants were included in the study of whom 47 (36%) underwent autistic regression at an average age of 20 months. The investigative procedures included electroencephalogram (n = 132), neuroimaging (n = 70), genetic studies to detect Fragile-X (n = 59) and a metabolic workup (n = 53). Except for the molecular diagnosis that revealed Fragile-X syndrome in two children (3%), all other tests were negative. The two infants with the Fragile-X syndrome belonged to the non-regressive group. Conclusions: The only investigative study that contributed to the diagnosis of autistic infants was the molecular diagnosis detecting Fragile-X. In spite of the high frequency of epilepsy and epileptiform abnormalities in the electroencephalograms of autistic children in general, the contribution of epilepsy, both clinical and subclinical, to the etiology of autism is apparently minimal.