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Objective: The pathogenesis of Autism spectrum disorders (ASD) is complex and still not clear. Genetic factors contribute to the occurrence of ASD. However, the genetics of ASD is highly heterogeneous. Chromosomal aberrations have a key role to the genetic abnormalities of both syndromic and non-syndromic ASD. Methods: In our study, we conducted karyotyping analysis in a sample of 231 Egyptian children with ASD aged 3-13 years (132 males and 99 females) from five Governorates in Upper Egypt. Results: Eleven patients (4.7%) were found to have chromosomal abnormalities in this study. We found five patients having sex chromosome aneuploidy, including two patients with Turner syndrome, two with 47XYY and one with 47XXY. In addition, we detected three patients have Down syndrome, one patient has monosomy 1p36, one patient has Williams-Beuren syndrome and one patient has a deletion of the long arm of chromosome 13. Conclusions: The present study reinforces the findings of the association between some chromosomal aberrations and ASD. Further investigations into these regions may lead to discovery of new genes involved in ASD. The present study directs the attention of the clinicians about the importance of karyotyping in the evaluation of ASD patients. [Anadolu Psikiyatri Derg 2017; 18(3.000): 243-249]