Sunday, March 6, 2011

Jaundice as a cause of ASD?

There has been recent interest in the possibility that jaundice causes autism. This interest has been stimulated by a publication identifying an association with autism and jaundice. Jaundice is the accumulation of blood cell break-down products (billirubin) in the body. In newborns, this is thought to be due to metabolic adjustments. In rare cases, neonatal jaundice can cause brain damage. The first striking aspect of this study is that despite jaundice prevalence of 60% in newborns, the autism prevalence in this study was about 5%. Also a disease called hemolytic disease causes an increase in billirubin but the incidence of ASD in this group was not investigated. Based on the jaundice hypothesis of ASD, it would be expected that there is a very high incidence of ASD in those with hemolytic disease. A further rebuttal of the jaundice hypothesis can be found here. If ASD is a multi-hit disorder - requiring at least two agents for one cause - then jaundice might be a candidate for one of the co-agents.