The Role of Epigenetic Modifications in Autism Spectrum Disorder

May 12, 2017 updated by: Rasha Mohammed Ali, Assiut University

The Role of Epigenetic Modifications in Autism Spectrum Disorder Through DNA Methylation

Autism Spectrum Disorder is a neurodevelopmental disorder characterized by impaired social communication and repetitive or stereotyped behaviors. According to the World Health Organization , the prevalence of Autism Spectrum Disorder is one person in 160.

Study Overview

Detailed Description

Genetic and non-genetic factors would contribute to the development of autism. However, the molecular mechanisms of ASD are not clear and successful treatments are still under research. Autism Spectrum Disorder can occur due to exposure to environmental pollutants which lead to epigenetic changes like DNA methylation, acetylation and post-translational modifications. However, the role of epigenetic changes in Autism Spectrum Disorder is still debated.

Epigenetic mechanisms represent a link through which environmental factors interact with the genetic factors resulting in modification of Autism Spectrum Disorder risk through changes in gene expression. DNA methylation and histone deacetylation are two major epigenetic mechanisms that regulate the gene expression at successive stages of brain development.

Brain derived neurotrophic factor is responsible for brain development. Altered BDNF levels and expression may be closely associated with Autism Spectrum Disorder. . Glial fibrillary acidic protein is the hallmark intermediate filament protein in astrocytes, the main type of glial cells in the central nervous system. Interestingly, Glial fibrillary acidic protein is a marker of astroglial activation and the recent data indicated that Glial fibrillary acidic protein could be implicated in the pathophysiology of autism. However, the underlying mechanisms for the role of brain derived neurotrophic factor and glial fibrillary acidic protein in autism spectrum disorder are poorly understood.

Study Type

Observational

Enrollment (Anticipated)

40

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact Backup

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

2 years to 6 years (Child)

Accepts Healthy Volunteers

N/A

Genders Eligible for Study

All

Sampling Method

Non-Probability Sample

Study Population

The children attending the pediatric clinic at Assiut University Hospital

Description

Inclusion Criteria:

  1. - All enrolled children with Autism Spectrum Disorder will be:

    1. Exhibit symptoms within the typical triad of autistic traits: communication impairment, social deficits, and ritualistic interests.
    2. Drug-naïve.
  2. Children with Autism Spectrum Disorder and controls will be 2-6 years old.

Exclusion Criteria:

The control subjects will also clinically examined by the psychiatrist to exclude any sub-clinical autistic features. Children with Autism Spectrum Disorder and controls will excluded from the study if

  1. They receive treatment for any reason.
  2. -Endocrinological disease, mental retardation, communication disorder, psychotic disorder, attention deficit hyperactivity disorder and learning disorders seen in the children or their family members.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Observational Models: Case-Control
  • Time Perspectives: Retrospective

Cohorts and Interventions

Group / Cohort
Intervention / Treatment
Autism Cases

20 confirmed autism cases will be involved in this study.

  1. The autism patients will be diagnosed according to:Gilliam Autism Rating Scale Arabic version: An assessment of the severity of autism using the Gilliam autism rating scale Arabic version: This test was used for diagnosis and assessment of the severity of autistic features for ages 3-22 years. It consists of 56 items, subdivided into 4 subscales: communication, social interaction, stereotyped behaviors, development and total score.
  2. Fasting blood samples will be collected from autism children for DNA Methylation-and quantitative Real-time Polymerase Chain Reaction Analysis

Fasting blood samples will be collected from both autism and controls for DNA extraction. Peripheral blood (2ml) will be drawn from the cubital vein intoplastic syringes. Lymphocytes will be isolated from blood samples. We will examine the gene methylation in the peripheral blood lymphocytes of drug-naı¨ve autism patients and control subjects.

DNA will be isolated from lymphocytes, purified and processed for bisulfate modification. Bisulfate treatment of genomic DNA will be performed using DNA methylation kit according to the manufacturer´ instructions. Bisulfite treatment of genomic DNA converts cytosine to uracil, but leaves methylated 5'Cytosines unchanged. Quantitative real time Polymerase chain reaction will be used to determine the DNA methylation status of the Brian derived neurotrophic factor and glia fibrillary acidic protein genes using primers specific to the human genes.

An assessment of the severity of autism using the Gilliam autism rating scale Arabic version: This test was used for diagnosis and assessment of the severity of autistic features for ages 3-22 years. It consists of 56 items, subdivided into 4 subscales: communication, social interaction, stereotyped behaviors, development and total score. The Arabic version has been validated with good reliability and validity and used in many studies before. The lower the scores are, the worse the condition is.

The scale will be done by trained and certified psychologist. The protocol and informed consent for this study will be reviewed and approved by the ethics committee at the Faculty of Medicine, Assiut University, Egypt.

Control

20 age-gender matched typical development children that will be assigned to the normal control group.

  1. Control children will be examined by a psychiatrist to exclude any sub-clinical autistic features.
  2. Fasting blood samples will be collected from control children for DNA Methylation-and quantitative Real-time Polymerase Chain Reaction Analysis

Fasting blood samples will be collected from both autism and controls for DNA extraction. Peripheral blood (2ml) will be drawn from the cubital vein intoplastic syringes. Lymphocytes will be isolated from blood samples. We will examine the gene methylation in the peripheral blood lymphocytes of drug-naı¨ve autism patients and control subjects.

DNA will be isolated from lymphocytes, purified and processed for bisulfate modification. Bisulfate treatment of genomic DNA will be performed using DNA methylation kit according to the manufacturer´ instructions. Bisulfite treatment of genomic DNA converts cytosine to uracil, but leaves methylated 5'Cytosines unchanged. Quantitative real time Polymerase chain reaction will be used to determine the DNA methylation status of the Brian derived neurotrophic factor and glia fibrillary acidic protein genes using primers specific to the human genes.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
The difference of percentage of DNA methylation of Brain derived neurotrophic factor gene and glial fibrillary acidic protein gene between the two groups
Time Frame: one year
Real Time Polymerase Chain Reaction
one year
The relation between the severity of autistic symptoms and percentage of Brain derived neurotrophic factor gene and glial fibrillary acidic protein gene methylation in Autism cases group
Time Frame: one year
correlation test
one year

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Anticipated)

September 1, 2017

Primary Completion (Anticipated)

September 1, 2018

Study Completion (Anticipated)

March 1, 2019

Study Registration Dates

First Submitted

May 12, 2017

First Submitted That Met QC Criteria

May 12, 2017

First Posted (Actual)

May 15, 2017

Study Record Updates

Last Update Posted (Actual)

May 15, 2017

Last Update Submitted That Met QC Criteria

May 12, 2017

Last Verified

May 1, 2017

More Information

Terms related to this study

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

No

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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