Scimex: US scientists have shed light on the factors that play a role in how severe autism develops, using animal research to link a newly discovered gene to this disorder. The gene plays a role in nerve development and the researchers suggest that its dysfunction could hamper the development of circuits in the brain and cognitive function, though they have yet to carry out similar work on humans.
A newly identified gene that is associated with severe autism
provides new clues about the factors that cause this neurodevelopmental
disorder. The gene, described in this week's Nature, has a role
in neuronal development. Some defects in this gene lead to impaired
development and maintenance of neural circuits in the brain, which may
impact cognitive function, and seem to contribute to rare severe cases
of autism in females.
Autism affects four times as many males as females; consequently, it is
hypothesised that females are affected only by severe variations to
autism genes that affect key developmental processes. To identify such
candidate genes, Tychele Turner, Aravinda Chakravarti and colleagues
analysed protein-coding genes in 13 females with severe autism. Despite
the small sample size, the authors identify 18 candidate genes that have
potentially harmful variants, including a gene calledCTNND2, which encodes a protein called delta-2 catenin.
Experiments in zebrafish and mice, model organisms for studying human disease, demonstrate
that loss of function of this gene has deleterious effects for the
development and/or maintenance of synapses. These findings highlight a
critical role for the CTNND2 gene in neuronal development and in autism.