Association Study between DUF1220 Copy Number and Severity of Social Impairment in Sex-balanced Simplex Cases of Autism.

Introduction: Copy number variations (CNVs), which are genetic factors responsible for human evolution, have emerged as underlying pathogenic factors for a number of diseases such as autism spectrum disorders (ASD). DUF1220 coding sequences have been shown to be positively associated with the severity of symptoms in familial/multiplex cases of autism. However, this association has not been confirmed in simplex autism, and the potential impact of gender/sex has not been studied. Methods: Using saliva samples taken from Iranian children with non-syndromic simplex autism, different ethnicity/race and genetic backgrounds from previous studies, we assessed the association between DUF1220 CNVs and Autism Diagnostic Interview-Revised (ADI-R) domain scores in both males and females. Results: In the male and female combined group with autism, in line with previous reports, our findings showed that there were no significant associations between DUF1220 CNVs with either total ADI-R score, social, communication, or repetitive diagnostic scores in simplex autism cases. Interestingly, however, in sex classified groups, despite the insignificant results, our findings in girls with autism showed a negative trend between DUF1220 CNVs and severity of symptoms for the social interaction and communication domains. By contrast, in male children with autism, the results showed a positive trend. Conclusion: It seems that association of DUF1220 CNV with the severity of symptoms in simplex children with autism may follow a sexually dimorphic pattern that needs to be re-examined in prospective studies.