Chromosomal abnormalities and autism

Abstract

Background: Autism is a neurodevelopmental disorder characterized by clinical, etiologic and genetic heterogeneity. Many surveys revealed cytogenetically visible chromosomal abnormalities in 7.4% of autistic patients documented as well as several submicroscopic variants. This study had been conducted to identify some aspects that might be involved in the pathogenesis of autism which is necessary for offering proper genetic counseling to families of autistic patients and their role in the prenatal diagnosis of autism.
Methods: This cross sectional study was conducted at the Child Psychiatry Clinic, Pediatric Hospital, Ain Shams University on 30 autistic patients who were subjected to the following tools: Confirmation of diagnosis using DSM-IV-TR criteria, IQ assessment using Stanford-Binet intelligence scale and assessment of severity of autistic symptoms using childhood autism rating scale (CARS). Full clinical examination, neurological examination, EEG, audiological assessment were also done. High resolution karyotyping was done for detection of numerical or structural chromosomal abnormalities as deletion, duplication, translocation of chromosomes.
Results: All the results of cytogenetic analysis were normal with no detectable numerical or structural chromosomal abnormalities. Males are affected more than females, only one case had history of drug intake (progestin), two cases had history of anti-D injection and two cases had history of diabetes mellitus during pregnancy. Four cases had history of respiratory distress and seven cases had history of jaundice. Two cases had history of generalized tonic clonic convulsion and four cases had history of EEG abnormalities. Fifteen cases of our autistic patients had mild mental retardation and six cases had moderate mental retardation.
Conclusion: Chromosomal abnormalities were not detected in the studied autistic children, and so the relation between the genetics and autism still needs further work up with different study methods and techniques.