Medical disorders among inpatients with autism in Denmark according to ICD-8: a nationwide register-based study.

Possible associations between autism and specific medical disorders have been suggested, and this could be of relevance in the clinical examination and treatment of patients and may help to identify factors involved in the etiology or pathophysiology of autism. Two population-based Danish registers were used to investigate the occurrence of medical disorders in patients with autism according to ICD-8 and in a matched control sample. A total of 29 of the 244 patients (11.9%) diagnosed with autism had one or more medical disorders. In contrast to previous studies, we did not find an increased occurrence of almost any medical disorders. A highly significant increased frequency of congenital malformations was found, which may indicate abnormalities in embryogenesis in the etiology of autism.