One hypothesis regarding the association between genetic changes, environmental factors and autism is that many mutations or polymorphisms make the organism more vulnerable to later exposure in some individuals. Called the “vulnerability phenotype”, the Noble lab hypothesizes that one potential unifying theme of the vulnerability phenotype of children with ASD is that they are more oxidized. This elevated oxidation state has been shown to be sufficient to cause dramatic changes in cellular function. In this project, Dr. Noble will test the hypotheses that genetically-based differences in oxidative status are associated with differences in vulnerability to physiological stressors in vitro and in vivo, with even greater increases in vulnerability to combinations of physiological stressors. Specifically, thimerosal and other vaccine adjuvants will be studied. The second part of the study will determine if these effects on a novel regulatory pathway called redox/Fyn/c-Cbl is a necessary mechanistic convergence for increases in vulnerability caused by a more oxidized metabolic status. These results will provide a better understanding of the biochemical effects and mechanisms of possible toxicity of vaccines and vaccine additives. What this means for people with autism: These studies will initially focus on the combination of vaccine additives, but then examine whether a background genetic vulnerability phenotype affects the response to these additives. The results would provide new targets for intervention against the adverse effects of increased oxidative status in children with autism.