ASD concordance of twins across DSM-IV-TR and DSM-5 diagnostic criteria

•Information from parent report (ADI-R) and clinical observation (ADOS) was used to calculate monozygotic pairwise concordance rates.•DSM-IV-TR diagnoses of pervasive developmental disorders and DSM-5 diagnoses of autism spectrum disorder were assigned to 14 twin pairs.•Sample pairwise concordance rates did not significantly differ across DSM-IV-TR and DSM-5 when using information from either or both measures.•Monozygotic pairwise concordance rates appear similar between DSM-IV-TR and DSM-5, but depend on whether strict or relaxed criteria were used.