According to US, autism genes are activated during fetal brain development. Autism-related mutations are connected to a pathway that regulates brain development.

This discovery was made when a set of well-known autism mutations called copy number variants or CNVs were being studied. These CNVs were later activated during a different stage in the development period of the brain. One that becomes active during the mid-fetal period were located in a region of the genome known as 16p11.2.


A network of genes showing a similar activation pattern including KCTD13 within 16p11.2 and CUL3, a gene from a different chromosome that is also mutated in autistic children were ultimately recognised.

The researchers later came to the realisation that proteins encoded by the genes, form a complex that regulates the levels of a third protein, RhoA, which is critical for neuronal migration and brain morphogenesis at early stages of brain development.

Timothy syndrome, a rare form of autism caused by the mutation in a completely different gene has also been linked to the RhOA pathway, which the scientists are planning to test using a stem cell model of autism.