Abstract

Association of contactin associated protein-like 2 (CNTNAP2) with its genetic variant (rs7794745) in Autistic Egyptian Children

Author(s): Asmaa El-Shemy1†,Hanan Anwar2, Asmaa Shukry3, Amany EL-falaha4, Sara Abdou5 and OLa Elshafey1

Background: Autism is a neurodevelopmental disorder with a complicated genetic background and a high heritability. The gene for Contactin-Associated Protein-Like 2 (CNTNAP2) is mainly presented in the developing brain and spinal cord. It encodes the neuronal protein CASPR2 (Contactin-Associated Protein-Like 2) and belongs to the neurexin superfamily. Objectives: to evaluate the association of Contactin-Associated Protein-Like 2 (CNTNAP2) with its genetic variant (rs7794745) in Egyptian Children with autism. Methods: 170 participants were included in this case-control study and divided into two groups (group I: 85 autistic patients, group II: 85 healthy volunteers matched in age and gender to serve as controls. Each participant underwent medical history, physical examination, clinical examination, laboratory tests, and assessment of patient severity using Children Autism Rating Scale (CARS). Quantitative estimation of serum CNTNAP2 level was done by Enzyme-Linked Immunosorbent Assay (ELISA). Genotyping of SNP rs7794745 in the CNTNAP2 gene was done by Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR-RFLP). Results: Patients with autism had significantly lower serum CNTNAP2 levels than controls (P<0.001). Patients carrying the TT genotype of CNTNAP2 (rs7794745) had increased risk for autism 4.05 times (P<0.046). In addition, patients carrying the T allele of CNTNAP2 (rs7794745) had increased risk for autism 1.75 times (P<0.022). Conclusion: The CNTNAP2 (rs7794745) gene variant (TT genotype and T allele) have been significantly associated with autism. So, this genetic variant in CNTNAP2 may contribute to autism susceptibility as a potential genetic risk marker.