IMMUNO PROFILE IN FRAGILE X AND AUTISM

Background: Fragile X syndrome (FXS) is a single-gene disorder with a broad spectrum of involvement and a strong association with autism. Approximately 2 to 6% of children with autism have FXS, and approximately 30% of children with FXS have autism. Altered immune responses have been described in autism and there is potential that in children with FXS and autism, an abnormal immune response may play a role. Indeed, an increased frequency of infections was reported in a subgroup of boys with FXS, especially in early childhood, which may underlie an aberrant or dysfunctional immune response.

Objectives: To delineate specific patterns of cytokine/chemokine profiles in individuals with FXS with and without autism and to compare them with individuals with autism without FXS, and with typical developing controls.

Methods: Age matched male subjects were recruited through the M.I.N.D. Institute and included: 20 subjects with autism, 19 typically developing controls, 64 subjects with FXS without autism and 40 subjects with FXS and autism. Autism diagnosis was confirmed with ADOS, ADI-R and DSM IV criteria. Plasma was isolated and cytokine and chemokine production was assessed by Luminex multiplex analysis.

Results: Preliminary observations indicate significant differences in plasma protein levels of a number of cytokines, including IL-1alpha, and several chemokines, including Eotaxin, RANTES and MIP1alpha, between the FXS group and the typical developing controls (p<0.05). In addition, significant differences were observed between the FXS group with autism and the FXS without autism for IL-6, Eotaxin, MCP-1 (p<0.04). There were also notable differences between FXS (with and without autism) and autism subjects.

Conclusions: The characterization of an immunological profile in FXS with and without autism may help to elucidate if an abnormal immune response may play a role and help to identify mechanisms important in the etiology of autism both with and without FXS.