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THURSDAY, Feb. 23 (HealthDay News) -- The siblings of children with autism or other pervasive developmental disorders may also have social impairment, particularly if they are from multiple-incidence families, according to a study in the February issue of the American Journal of Psychiatry.
John N. Constantino, M.D., of Washington University School of Medicine in St. Louis, Mo., and colleagues obtained assessments of autistic social impairment in three groups of proband-sibling pairs: autistic children from multiple-incidence families and their closest-in-age non-autistic brothers (49 pairs); children with any pervasive developmental disorder, including autism, and their closest-in-age brothers (100 pairs); and children with psychopathology unrelated to autism and their closest-in-age brothers (45 pairs).
In the autistic and pervasive developmental disorder groups, the researchers discovered substantially elevated impairment in siblings. They saw the greatest impairment in the siblings of autistic probands from multiple-incidence families, followed by the siblings of probands with pervasive developmental disorder. The lowest impairment was in siblings of probands with psychopathology unrelated to autism.
"Taken together with previous findings, these results support the notion that genetic susceptibility factors responsible for common, subsyndromal social impairments may be related to the causes of categorically defined pervasive developmental disorders," the authors conclude.