Crusio has recently looked into the possibility that "FMR1" knockout mice can perhaps be used as a model for autism. The Fragile X syndrome is caused by a deficiency of the "FMR1" gene. Patients often show autistic symptoms. A good mouse model for the Fragile X syndrome is available because there are mice in which the "Fmr1" gene has been changed so that it does not work any more. A review of the work that has been done with these mice in many different laboratorie did indeed show that these animals have autistic-like symptoms. For example, they show changes in social behavior and this is a key symptom of autism.