The G22A Polymorphism of the ADA Gene and Susceptibility to Autism Spectrum Disorders
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Inborn errors of purine metabolism have been implicated as a cause for some cases of autism. This hypothesis is supported by the finding of decreased adenosine deaminase (ADA) activity in the sera of some children with autism and reports of an association of the A allele of the ADA G22A (Asp8Asn) polymorphism in individuals with autism of Italian-descent. We tested the ADA G22A polymorphism in 126 North American affected sib-pair families but found no aberrant allele distributions in cases versus controls. Instead, we found an increased transmission of the G allele from fathers to affected children. Our findings suggest that the ADA G22A polymorphism plays a minimal role in susceptibility to autism in North American families.
KeywordsAutism spectrum disorders Candidate gene Adenosine deaminase Purine metabolism Hyperuricosuria
The authors are very grateful to the families who participated in this research and we gratefully acknowledge the resources provided by the Autism Genetic Resource Exchange (AGRE) Consortium and the participating AGRE families. The Autism Genetic Resource Exchange is a program of Cure Autism Now and is supported, in part, by grant MH64547 from the National Institute of Mental Health to Daniel H. Geschwind (PI).
This work was supported by research grants from the Ontario Mental Health Foundation (to JJAH) and the Canadian Institutes for Health Research (#43820) to the Autism Spectrum Disorders Canadian-American Research Consortium (ASD-CARC) (JJAH, PI; www.asdcarc.com; www.autismresearch.ca) and a research studentship from the Ontario Mental Health Foundation to JAH. JAH is a trainee with the CIHR/NAAR STIHR Interdisciplinary Inter-Institute Autism Spectrum Disorders Training Program (PI: JJAH).
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