Social behavior and cortisol reactivity in children with fragile X syndrome.
OBJECTIVE
To examine the association between limbic-hypothalamic-pituitary-adrenal (L-HPA) axis reactivity and social behavior in children with fragile X syndrome (FXS).


METHODS
Salivary cortisol changes and concurrent anxiety-related behaviors consistent with the behavioral phenotype of FXS were measured in 90 children with the fragile X full mutation and their 90 unaffected siblings during a social challenge task in the home.


RESULTS
Boys and girls with FXS demonstrated more gaze aversion, task avoidance, behavioral signs of distress, and poorer vocal quality than the unaffected siblings. Multiple regression analyses showed that after accounting for effects of IQ, gender, age, quality of the home environment, and basal cortisol level, cortisol reactivity to the task was significantly associated with social gaze in children with FXS. The most gaze-aversive children with FXS had cortisol reductions, whereas those with more eye contact demonstrated the most cortisol reactivity. Unaffected siblings demonstrated an opposite pattern in which less eye contact was associated with increased cortisol reactivity.


CONCLUSIONS
Results of the study suggest a unique relation between abnormal gaze behavior and L-HPA mediated stress reactivity in FXS.
Hessl
David
D
M.I.N.D. Institute, USA.
Glaser
Bronwyn
B
Dyer-Friedman
Jennifer
J
Reiss
Allan L
AL
D002648:Child; D005260:Female; D051860:Fragile X Messenger Ribonucleoprotein 1 / Q000235:genetics; D005600:Fragile X Syndrome / Q000453:epidemiology / Q000235:genetics / Q000503:physiopathology*; D006801:Humans; D006854:Hydrocortisone / Q000032:analysis / Q000378:metabolism*; D007030:Hypothalamo-Hypophyseal System / Q000378:metabolism / Q000503:physiopathology; D008297:Male; D010641:Phenotype; D010698:Phobic Disorders / Q000453:epidemiology / Q000378:metabolism / Q000523:psychology; D010913:Pituitary-Adrenal System / Q000378:metabolism / Q000503:physiopathology; D017354:Point Mutation / Q000235:genetics; D012463:Saliva / Q000737:chemistry; D012919:Social Behavior
D051860:Fragile X Messenger Ribonucleoprotein 1; D006854:Hydrocortisone; C497683:FMR1 protein, human