Levels of cerebrospinal fluid nerve-growth factor differ in infantile autism and Rett syndrome

Autism and Rett syndrome (RS) are both developmental disorders of unknown o rigin. Autism is a behaviourally defined syndrome. RS, which affects girls only, is characterized by a profound learning disability following early no rmal development, with a consistent cluster of clinical features. Different iation of RS from infantile autism in the very early stages of the disorder s is not always easy. Both syndromes still lack discriminative laboratory m arkers for accurate diagnosis and differentiation. We decided to compare th e CSF nerve-growth factor (NGF) levels of children with infantile autism an d children with RS using enzyme-linked immunosorbent assay (ELISA). Our fin dings of mainly normal CSF NGF in autism and low to negligible values in RS are in agreement with the different morphological and neurochemical findin gs (brain growth, affected brain areas, neurotransmitter metabolism) in the two syndromes. CSF NGF could be used as a biochemical marker for different iation of patients with autism from those with RS.