Autism spectrum disorders (ASDs) is characterized by impairment in social interaction, abnormalities in language development, restricted interest and/or repetitive behaviors. The etiology and pathogenesis of autism are not fully elucidated. It has been thought that environmental, immunologic, genetic, prenatal, early postnatal and biochemical events play role in the etiology. Its concordance is reported as 64% in monozygotic twins and 9% in dizygotic twins. In this case report, we will discuss 2 distinct dizygotic twins diagnosed as autism.
Case 1: Twins aged 3 years and 5 months were referred to our outpatient clinic. The girl was suffering from failure to speak. In the history obtained from parents, it was found that she didn’t respond to her name; that she didn’t establish eye contact; that she interested herself; that she continuously watched music channels; that she had no emotional sharing; that she whirled around; that she watched spinning washing machine for prolonged periods; and that she displayed repetitive movements such as hand şapping, when she was excited or happy. In her examination, it was found that she did not establish communication; that she did not response to her name; and that she displayed stereotypical movements as hand şapping. The patient was diagnosed autism. The boy was suffering from similar symptoms but his communication was better when compared to his sister. In his examination, it was seen that his communication was limited but better than his sister was. He was diagnosed as atypical autism. Special education was recommended to both cases.
Case 2: Twins aged 8 years and 6 months were referred to our outpatient clinic. The boy was suffering from self-harming, uneasiness, and irritability. In his psychiatric examination, it was seen that he had agitation; that he had no eye contact, stereotypies of jumping and hand şapping. The girl was suffering from unappeasable crying and harming friends. In her physical examination, it was found that she was agitated and had limited eye contact. When developmental and premorbid history was questioned, it was found out that twins had referred to a pediatrician when they were 3 years old. The boy was diagnosed as autism while the girl was diagnosed as atypical autism. In both cases, 1 mg/kg aripiprazole was initiated. Aripiprazole doses were escalated to 4 mg/kg in the boy and 2 mg/kg in the girl.
Discussion: Until today, it was failed to identify a single, major gene responsible from autism in the linkage and correlation studies. This indicates that autism is a complex, genetic disease, displaying heterogeneity. It was found that risk for autism is 30 to 150-folds higher in the siblings of autistic patients when compared to siblings of healthy individuals. It has been suggested that the risk is even higher in monozygotic and dizygotic twins. Our cases also supported this information. The distinct weights of autism in dizygotic twins in our cases demonstrate that there were different factors inşuencing clinical presentation of autism in addition to genetic mechanisms.