doi:10.1038/nindia.2015.124 Published online 4 September 2015
Researchers have identified certain proteins that are abnormally expressed in the urine of autistic children, making them promising as biomarkers for diagnosing autism in children1.
Autism is a complex developmental disability that affects normal brain function and results in loss of social interaction skills. As the exact cause of autism is unknown, it is difficult to identify disease biomarkers for autistic children.
In the present study, the researchers measured abnormally expressed proteins in the urine of Indian autistic children and compared them with those of normal children.
The scientists found that autistic children excreted greater number of proteins in their urine than normal children. In spectroscopic analysis, they identified 250 protein-specific spots for autistic children but only 159 such spots for normal children.
The researchers attributed this higher number of proteins in the urine of autistic children to defective intestinal function, which caused partially broken dietary proteins to enter the bloodstream and to be excreted through urine. Of the proteins, three — kininogen-1, IgG1 heavy chain variable region and mannan-binding lectin serine protease-2 isoform-2 precursor — were found to be abnormally excreted in autistic children, suggesting that they could be used as biomarkers for autism.
Of these three proteins, kininogen-1 seems the most promising as a potential diagnostic marker for autism, the researchers say.
1. Vijayashankar, S. et al. Urine proteome analysis to evaluate protein biomarkers in children with autism. Clin. Chim. Acta (2015) doi:10.1016/j.cca.2015.08.015