Israel Medical Association Journal

Objectives: To devise a clinical classification of children diagnosed with ASD according to etiologic workup.

Methods: Children diagnosed with ASD (n=436) from two databases were divided into groups of symptomatic, cryptogenic or idiopathic, and variables within each database and diagnostic category were compared.

Results: By analyzing the two separate databases, 5.4% of the children were classified as symptomatic, 27% as cryptogenic and 67.75% as idiopathic. Among other findings, the entire symptomatic group demonstrated language delays, but almost none showed evidence for regression. Our results indicate similarities between the idiopathic and cryptogenic subgroups in most of the examined variables, and mutual differences from the symptomatic subgroup. The similarities between the first two subgroups support prior evidence that most perinatal factors and minor physical anomalies do not contribute to the development of core symptoms of autism. Conclusions: Differences in gender and clinical and diagnostic features were found when etiology was used to create subtypes of ASD. This classification could have heuristic importance in the search for an autism gene(s).

Background: Studies from many countries have reported an increasing prevalence of autistic spectrum disorder in childhood. No comprehensive epidemiological studies of ASD[1] have been performed in Israel.

Objectives: To describe time trends in the reported number of patients with ASD in Israel and to characterize the demographic features of the reported patients.

Methods: We reviewed the charts of the National Insurance Institute of Israel from 1972 to 2004 for all children with a diagnosis of ASD receiving disability benefits.

Results: A total of 3509 children met the study criteria. Eighty percent were boys and 98% were Jewish. The incidence data showed an increase in the number of cases from zero in 1982–84 and 2 (1.2 per million capita under 18 years) in 1985 to a high of 428 cases in 2004 (190 per million).

Conclusions: This is the first comprehensive study of the incidence of ASD in Israel. According to data derived from official health records, the rate of occurrence of ASD has substantially increased in the last 20 years. Further studies are needed to determine if this is a true increase or if the findings were confounded by external factors, such as recent improvements in diagnostic measures and social stigmas.