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Evaluating mitochondrial DNA variation in autism spectrum disorders
Athena Hadjixenofontos1, Michael A Schmidt, Patrice L Whitehead
1John P. Hussman Institute for Human Genomics, University of Miami, Miller School of Medicine, Miami, FL 33136, USA.
Annals of Human Genetics
|November 8, 2012
Summary
This study investigated mitochondrial DNA (mtDNA) variations and their link to Autism Spectrum Disorders (ASD). Researchers found no significant evidence that mtDNA variations play a major role in ASD susceptibility.
Area of Science:
- Genetics
- Neurodevelopmental Disorders
- Mitochondrial Biology
Background:
- Oxidative stress and abnormal energy metabolism are speculated to be involved in Autism Spectrum Disorders (ASD).
- Patients with mitochondrial defects exhibit symptoms consistent with ASD.
- Comprehensive studies on the role of mitochondrial DNA (mtDNA) variation in autism risk are lacking.
Purpose of the Study:
- To comprehensively examine the role of mitochondrial DNA (mtDNA) variation in Autism Spectrum Disorders (ASD) risk.
- To investigate the association between mtDNA variations and ASD susceptibility.
Main Methods:
- A multi-phase approach was employed to analyze mtDNA variation in ASD.
- Phase 1: Examined 132 mtDNA single-nucleotide polymorphisms (SNPs) from genome-wide association studies of ASD.
- Phase 2: Genotyped major European mitochondrial haplogroup-defining variants in a larger cohort of ASD probands and controls.
- Phase 3: Sequenced the entire mtDNA in approximately 400 Caucasian proband-father pairs.
Main Results:
- Despite thorough investigation across all phases, no significant association was found between mtDNA variation and ASD.
- No evidence suggests that mtDNA variation is a major contributing factor to ASD development.
Conclusions:
- Mitochondrial DNA (mtDNA) variation does not appear to be a significant risk factor for Autism Spectrum Disorders (ASD).
- While biological hypotheses suggest a role for mitochondria in ASD, this study's data do not support mtDNA variation as a primary cause.
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