Genetics: Study ties three immune genes to autism
Common variants in three genes involved in the immune system are more likely to crop up in people with autism than in typical controls, according to a study published 9 June in Molecular Autism1.
In the new study, researchers used a bioinformatics database called Ingenuity Pathway Analysis to identify 2,012 genes with known roles in the immune system. They then searched for common variants in those genes in blood samples taken from 1,510 trios (two parents and a child with autism) from the Autism Genetic Resource Exchange, a genetic repository that includes families with at least two children who have autism.
Common variants in three genes — CD99L2, JARID2 and TPO — are significantly more common in the individuals with autism than in their unaffected parents, the study found.
All three genes have several biological roles, in the immune system and elsewhere. CD99L2 encodes a molecule involved in the movement of white blood cells during the process of tissue inflammation. JARID2, which helps remove methyl marks from histones, has previously been tied to schizophrenia2 and autism3. TPO encodes an enzyme important for normal function of the thyroid gland.
Interestingly, when looking at the set of immune system genes as a whole, the researchers found no statistically significant enrichment in the autism group compared with controls. This shows the value in investigating the associations of individual genes, they say.
1: Ramos P.S. et al. Mol. Autism 3, 4 (2012) PubMed
2: Pedrosa E. et al. Am. J. Med. Genet. B Neuropsychiatr. Genet. 144B, 45-51 (2007) PubMed
3: Weiss L.A. et al. Nature 461, 802-808 (2009) PubMed