Is autism caused by early hyperactivity of brain-derived neurotrophic factor?

Med Hypotheses. 2005;65(1):79-82. doi: 10.1016/j.mehy.2005.01.034.


Autism, a childhood-onset neurodevelopmental disorder, is characterized by disturbances in socialization and language skills, as well as in perception. Several studies indicate the importance of both genetic and environmental factors in the development of idiopathic autism, but the underlying pathogenesis of this disorder is still unknown. Brain-derived neurotrophic factor (BDNF) is important for normal neuronal development. Early BDNF hyperactivity may play an etiological role in autism early in life. This hypothesis is supported by the finding that serum and brain tissue BDNF levels are increased in autism compared with normal controls. Furthermore, BDNF hyperactivity may be associated with early brain outgrowth, increased prevalence of seizures in autism, and similar behaviors observed in autism and fragile X syndrome. Further studies of serum BDNF levels and genetic studies of the BDNF signaling pathway may help to clarify the role of BDNF in the pathogenesis of autism. Attempts to prove the BDNF hyperactivity hypothesis may lead investigators in a new direction for the study of the pathogenesis of autism and the development of an effective intervention of this disorder.

Publication types

  • Comparative Study

MeSH terms

  • Alleles
  • Amino Acid Substitution
  • Autistic Disorder / etiology*
  • Autistic Disorder / genetics
  • Autistic Disorder / pathology
  • Brain / metabolism*
  • Brain Chemistry / genetics
  • Brain Chemistry / physiology
  • Brain-Derived Neurotrophic Factor / blood
  • Brain-Derived Neurotrophic Factor / chemistry
  • Brain-Derived Neurotrophic Factor / genetics
  • Brain-Derived Neurotrophic Factor / metabolism*
  • Child
  • Child, Preschool
  • Dimerization
  • Dinucleotide Repeats
  • Heterozygote
  • Humans
  • Methionine / metabolism
  • Models, Biological
  • Polymorphism, Genetic
  • Polymorphism, Single Nucleotide
  • Protein Structure, Tertiary
  • Receptor, trkB / metabolism


  • Brain-Derived Neurotrophic Factor
  • Methionine
  • Receptor, trkB