Increased prevalence of familial autoimmunity in probands with pervasive developmental disorders.
OBJECTIVE
Increased prevalence of familial autoimmune disease is a common finding among probands with various autoimmune disorders. Autistic disorder (autism) is a highly genetic disorder with known immune and immunogenetic abnormalities. Previous research has found an increased frequency of autoimmune disorders in families with autistic probands. We further investigated this association by determining the frequency of autoimmune disorders in families that have probands with pervasive developmental disorders (PDDs), including autism, compared with 2 control groups.


METHODS
Three well-defined study groups, including 1) families that have a child with a PDD, 2) families that have a child with an autoimmune disorder, and 3) families with a healthy control child, constituted the sample. A questionnaire inquiring about which first- and second-degree family members had received a diagnosis of having specific autoimmune disorders was completed by 101 families in each group.


RESULTS
The frequency of autoimmune disorders was significantly higher in families of the PDD probands compared with families of both the autoimmune and healthy control probands. Autoimmunity was highest among the parents of PDD probands compared with parents of the healthy control subjects. Hypothyroidism/Hashimoto's thyroiditis and rheumatic fever were significantly more common in families with PDD probands than in the healthy control families.


CONCLUSIONS
Autoimmunity was increased significantly in families with PDD compared with those of healthy and autoimmune control subjects. These preliminary findings warrant additional investigation into immune and autoimmune mechanisms in autism.
Department of Psychiatry, Indiana University School of Medicine, and James Whitcomb Riley Hospital for Children Indianapolis 46202-4800, USA.
Thayne L
TL
Sweeten
Suzanne L
SL
Bowyer
David J
DJ
Posey
Gary M
GM
Halberstadt
Christopher J
CJ
McDougle
D000293:Adolescent; D001321:Autistic Disorder / Q000453:epidemiology / Q000235:genetics / Q000276:immunology; D001327:Autoimmune Diseases / Q000453:epidemiology* / Q000235:genetics; D002648:Child; D002659:Child Development Disorders, Pervasive / Q000453:epidemiology* / Q000235:genetics / Q000276:immunology; D005260:Female; D020022:Genetic Predisposition to Disease; D006801:Humans; D008297:Male; D015995:Prevalence; D011795:Surveys and Questionnaires