A University of California study has determined the link between a newly identified gene and idiopathic (non syndromic) autism. The gene, called TRPC6, is associated with Rett syndrome, a syndromic form of autism, suggesting that different types of autism spectrum disorder (ASD) may share similar molecular pathways.
“I see this research as an example of what can be done for cases of non-syndromic autism, which lack a definitive group of identifying symptoms or characteristics,” said principal investigator Alysson Muotri, PhD, associate professor in the UC San Diego departments of Pediatrics and Cellular and Molecular Medicine. “One can take advantage of genomics to map all mutant genes in the patient and then use their own iPSCs to measure the impact of these mutations in relevant cell types. Moreover, the study of brain cells derived from these iPSCs can reveal potential therapeutic drugs tailored to the individual. It is the rise of personalized medicine for mental/neurological disorders.”
The researchers for this study developed a tooth fairy project where parents provided discarded baby teeth from their autistic child. Scientists extract dental pulp cells from the tooth and differentiate them into iPSC-derived neurons for study.
Research findings reveal a disruption in one of the two copies of the TRPC6 gene in iPSC-derived neurons of a non-syndromic autistic child. Mouse models established that mutations in TRPC6 resulted in altered neuronal development, morphology and function.
“Taken together, these findings suggest that TRPC6 is a novel predisposing gene for ASD that may act in a multiple-hit model,” Muotri said. “This is the first study to use iPSC-derived human neurons to model non-syndromic ASD and illustrate the potential of modeling genetically complex sporadic diseases using such cells.”
K Griesi-Oliveira, A Acab, A R Gupta, D Y Sunaga, T Chailangkarn, X Nicol, Y Nunez, M F Walker, J D Murdoch, S J Sanders, T V Fernandez, W Ji, R P Lifton, E Vadasz, A Dietrich, D Pradhan, H Song, G-l Ming, X Gu, G Haddad, M C N Marchetto, N Spitzer, M R Passos-Bueno, M W State, A R Muotri. Modeling non-syndromic autism and the impact of TRPC6 disruption in human neurons. Molecular Psychiatry, 2014; DOI: 10.1038/mp.2014.141