One of the features of the fragile X mouse model which is relevant to the human fragile X syndrome (and autism) is social behavior. Several tests show consistent social behavioral abnormalities in the fragile X mouse model. With a $140,000 grant from FRAXA Research Foundation in 2012-2013, Dr. Willemsen at Erasmus University used social behavior tests to measure the effectiveness of several drug strategies.
With $155,000 in grants from FRAXA Research Foundation over several years, Dr. Miklos Toth of Cornell University discovered increased startle response in fragile X mice and that baclofen can correct this phenotype. They also studied epigenetics (ie factors other than the gene itself) which can determine symptom severity in fragile X.