Analysis of Global and Local DNA Methylation Patterns in Blood Samples of Patients With Autism Spectrum Disorder

María Victoria García-Ortiz; María José de la Torre-Aguilar; Teresa Morales-Ruiz; Antonio Gómez-Fernández; Katherine Flores-Rojas; Mercedes Gil-Campos; Pilar Martin-Borreguero; Rafael R Ariza; Teresa Roldán-Arjona; Juan Luis Perez-Navero

doi:10.3389/fped.2021.685310

Analysis of Global and Local DNA Methylation Patterns in Blood Samples of Patients With Autism Spectrum Disorder

Front Pediatr. 2021 Oct 5:9:685310. doi: 10.3389/fped.2021.685310. eCollection 2021.

Authors

María Victoria García-Ortiz^{1

2

3}, María José de la Torre-Aguilar^{1

4}, Teresa Morales-Ruiz^{1

2

3}, Antonio Gómez-Fernández^{1

4}, Katherine Flores-Rojas^{1

5

6}, Mercedes Gil-Campos^{1

5

6}, Pilar Martin-Borreguero^{1

7}, Rafael R Ariza^{1

2

3}, Teresa Roldán-Arjona^{1

2

3}, Juan Luis Perez-Navero^{1

4

8}

Affiliations

¹ Maimónides Biomedical Research Institute of Córdoba (IMIBIC), Córdoba, Spain.
² Department of Genetics, University of Córdoba, Córdoba, Spain.
³ Reina Sofía University Hospital, Córdoba, Spain.
⁴ Department of Pediatrics, Reina Sofia University Hospital, University of Córdoba, Córdoba, Spain.
⁵ Pediatric Metabolism Unit, Reina Sofia University Hospital, University of Córdoba, Córdoba, Spain.
⁶ Physiopathology of Obesity and Nutrition Networking Biomedical Research Center (CIBEROBN), Córdoba, Spain.
⁷ Department of Child and Adolescent Clinical Psychiatry and Psychology, Reina Sofia University Hospital, Córdoba, Spain.
⁸ Biomedical Research Center-Rare Diseases (CIBERER), Carlos III Health Institute, Madrid, Spain.

Abstract

The goal of this investigation was to determine whether there are alterations in DNA methylation patterns in children with autism spectrum disorder (ASD). Material and Methods: Controlled prospective observational case-control study. Within the ASD group, children were sub-classified based on the presence (AMR subgroup) or absence (ANMR subgroup) of neurodevelopmental regression during the first 2 years of life. We analyzed the global levels of DNA methylation, reflected in LINE-1, and the local DNA methylation pattern in two candidate genes, Neural Cell Adhesion Molecule (NCAM1) and Nerve Growth Factor (NGF) that, according to our previous studies, might be associated to an increased risk for ASD. For this purpose, we utilized blood samples from pediatric patients with ASD (n = 53) and their corresponding controls (n = 45). Results: We observed a slight decrease in methylation levels of LINE-1 in the ASD group, compared to the control group. One of the CpG in LINE-1 (GenBank accession no.X58075, nucleotide position 329) was the main responsible for such reduction, highly significant in the ASD subgroup of children with AMR (p < 0.05). Furthermore, we detected higher NCAM1 methylation levels in ASD children, compared to healthy children (p < 0.001). The data, moreover, showed higher NGF methylation levels in the AMR subgroup, compared to the control group and the ANMR subgroup. These results are consistent with our prior study, in which lower plasma levels of NCAM1 and higher levels of NGF were found in the ANMR subgroup, compared to the subgroup that comprised neurotypically developing children. Conclusions: We have provided new clues about the epigenetic changes that occur in ASD, and suggest two potential epigenetic biomarkers that would facilitate the diagnosis of the disorder. We similarly present with evidence of a clear differentiation in DNA methylation between the ASD subgroups, with or without mental regression.

Keywords: DNA methylation patterns; NCAM; NGF; autism spectrum disorder; neurodevelopmental regression.