indicators of compared with same-aged 2-12 y ASD, PDD-NOS, NT children. neurotypical (NT) Combined Z-score controls measure had 33% and 21% sensitivity for autism and PDD-NOS, respectively, with 100% specificity. Heme Synthesis Woods et al. ASD 100 Mean porphyrin Elevated , Pathway Metabolite [63] PDD 27 and mercury hexacarboxyl- and pentacarboxyl-, Environ Controls levels were pentacarboxyl- porphyrin precopro- and Health 117 evaluated concentrations were Perspect between autism, associated with autism but 2-12 y PDD and NT not PDD-NOS. cP= coproporphyrin; cP I= coproporphyrin I; cP III=coproporphyrin III; penta=pentacarboxyl ASD= autism spectrum disorders; ATEC= Autism Treatment Evaluation Checklist; GSSG=oxidized glutathione; NT= neurotypical; PDD-NOS= pervasive developmental disorder otherwise specified; –not y= years of age 8. Studies that did Show that Mercury Body Burden Biomarkers Correlate with ASD Severity not Biomarker Authors and N Purpose of Study Findings Journal Age Heme Shandley et al. ASD 70 Investigated Analyses did to not Synthesis [77] Siblings 36 whether porphyrin find support for the Pathway Autism Res Controls 54 profiles can reliably hypotheses that Metabolite be used to (a) porphyrin levels 2-6 y differentiate ASD could be used as a from healthy valid tool to detect controls; and (b) ASD cases or predict predict ASD severity severity
2-12 y indicators of ASD, PDD-NOS, neurotypical (NT) controls compared with same-aged NT children. Combined Z-score measure had 33% and 21% sensitivity for autism and PDD-NOS, respectively, with 100% specificity. Heme Synthesis Pathway Metabolite pentacarboxyl-, precopro- and Woods et al. [63] Environ Health Perspect ASD 100 PDD 27 Controls 117 2-12 y Mean porphyrin and mercury levels were evaluated between autism, PDD and NT Elevated , hexacarboxyl- and pentacarboxyl- porphyrin concentrations were associated with autism but not PDD-NOS. cP= coproporphyrin; cP I= coproporphyrin I; cP III=coproporphyrin III; penta=pentacarboxyl ASD= autism spectrum disorders; ATEC= Autism Treatment Evaluation Checklist; GSSG=oxidized glutathione; NT= neurotypical; PDD-NOS= pervasive developmental disorder –not otherwise specified; y= years of age 8. Studies that did not Show that Mercury Body Burden Biomarkers Correlate with ASD Severity Biomarker Authors and Journal N Age Purpose of Study Findings Heme Synthesis Pathway Metabolite Shandley et al. [77] Autism Res ASD 70 Siblings 36 Controls 54 2-6 y Investigated whether porphyrin profiles can reliably be used to (a) differentiate ASD from healthy controls; and (b) predict ASD severity Analyses did not to find support for the hypotheses that porphyrin levels could be used as a valid tool to detect ASD cases or predict severity