A new study published in the Molecular Psychiatry journal, has revealed that a new gene plays a crucial role during early development in humans and may induce expression of characteristic autistic traits. ASD is a heterogenous disorder with only one percent of each individual ASD gene linked to ASD symptoms.
The researchers used olfactory stem cell models obtained from nasal biopsies to determine the new genes involved in ASD. The research revealed that the gene coding for the MOCOS (Molybdenum Cofactor Sulfurase) enzyme was under-expressed in stem cells from nine out of eleven of the ASD adults studied.
MOCOS has been associated with immunity and inflammation as well as the destruction of free radicals. The analysis of different tissues has identified MOCOS expression in the brain cells and intestine of several species, and notably the C. elegans worm and mammals. The groundbreaking study for the first time has revealed expression of the MOCOS protein in brain tissue and is linked to hypersensitivity to oxidative stress (i.e. to the toxicity of free radicals), a smaller number of synapses and abnormal neurotransmission due to a reduction in the number of vesicles carrying neurotransmitters.
The involvement of this enzyme in susceptibility to oxidative stress, which has frequently been observed in autistic children, its association with gastrointestinal diseases and its role in nerve development and neurotransmission suggests that it produces many of the symptoms that characterize ASD .
Olfactory stem cells reveal MOCOS as a new player in autism spectrum disorders, F. Féron, B. Gepner, E. Lacassagne, D. Stephan, B. Mesnage, M-P. Blanchard, N. Boulanger, C. Tardif, A. Devèze, S. Rousseau, K. Suzuki, JC. Izpisua Belmonte, M. Khrestchatisky, E. Nivet and M. Erard-Garcia, Molecular Psychiatry, doi: 10.1038/mp.2015.106, published online 4 August 2015.