Broca's Area Asymmetry and Language Deficits in Autism

improved recognition of the symptoms, greater parental concern, and possible epigenetic factors and modifications of gene expression. The theory that the measles-mumps-rubella (MMR) vaccine and thimerosol were responsible for the apparent increased prevalence of autism has largely been put to rest (Madsen KM et al. Pediatrics 2003;112:604-606; Smeeth L et al. Lancet 2004;364:963-969). ASD has a strong genetic basis, and a specific medical cause or environmental trigger is found in only 6-10% of cases, eg. prenatal insult, metabolic and toxic disorders, tuberous sclerosis, and postnatal encephalitis (Baird G et al. BMJ 2003;327:488-493; see Ped Neur Briefs October 2003;17:79-80). The study of the etiology of autism is multifaceted, and future research will involve pediatric neurologist, psychiatrist, pathologist, and geneticist.