Oxidative Stress and the Metabolic Pathology of Autism

Abstract

Chronic metabolic imbalance in the cellular microenvironment is often a primary factor in the development of complex disease. An integrated metabolic profile reflects the combined influence of genetic, epigenetic, and environmental factors that affect the candidate pathway of interest. In this way, the metabolic phenotype of an individual reflects the combined influence of both endogenous and exogenous factors on genotype and provides a window through which the cumulative impact of genes and environment may be viewed. Although both genetic and environmental factors appear to be necessary, in the majority of cases neither is independently sufficient for the autistic phenotype. A metabolic endophenotype provides an intermediate biomarker that is influenced by both genes and environment and can offer insights into relevant candidate genes and pathways. Moreover, chronic or systemic metabolic imbalance can leave a metabolic footprint that can be followed analytically to gain mechanistic insights into the pathophysiology and pathogenesis of autism and thereby open new windows for therapeutic intervention. Escalating evidence suggests that many autistic children may be under chronic oxidative stress. The scientific question posed in this chapter is whether the autism phenotype reflects multiple and variable susceptibility alleles that converge to create a fragile, environmentally sensitive homeostasis with diminished ability to control and resolve pro-oxidant exposures.