An Investigation of Porphyrinuria in Australian Children with Autism

Two recent studies, from France (Nataf et al., 2006 Nataf, R., Skorupka, C., Amet, L., Lam, A., Springbett, A. and Lathe, R. 2006. Porphyrinuria in childhood autistic disorder: Implications for environmental toxicity. Toxicol. Appl. Pharmacol., 214: 99–108. [Crossref], [PubMed], [Web of Science ®] , [Google Scholar]) and the United States (Geier & Geier, 2007 Geier, D. A. and Geier, M. R. 2007. A prospective study of mercury toxicity biomarkers in autistic spectrum disorders. J. Toxicol. Environ. Health, A, 70: 1723–1730. [Taylor & Francis Online], [Web of Science ®] , [Google Scholar]), identified atypical urinary porphyrin profiles in children with an autism spectrum disorder (ASD). These profiles serve as an indirect measure of environmental toxicity generally, and mercury (Hg) toxicity specifically, with the latter being a variable proposed as a causal mechanism of ASD (Bernard et al., 2001 Bernard, S., Enayati, A., Redwood, L., Roger, H. and Binstock, T. 2001. Autism: A novel form of mercury poisoning. Med. Hypoth., 56: 462–471. [Crossref], [PubMed], [Web of Science ®] , [Google Scholar]; Mutter et al., 2005 Mutter, J., Naumann, J., Schneider, R., Walach, H. and Haley, B. 2005. Mercury and autism: Accelerating evidence?. Neuroendocrinol. Lett., 26: 439–446. [PubMed], [Web of Science ®] , [Google Scholar]). To examine whether this phenomenon occurred in a sample of Australian children with ASD, an analysis of urinary porphyrin profiles was conducted. A consistent trend in abnormal porphyrin levels was evidenced when data was compared with those previously reported in the literature. The results are suggestive of environmental toxic exposure impairing heme synthesis. Three independent studies from three continents have now demonstrated that porphyrinuria is concomitant with ASD, and that Hg may be a likely xenobiotic to produce porphyrin profiles of this nature.