A recent study identified a new gene associated with severe autism. The gene (delta-2 catenin or CTNND2) provides new clues about the factors that cause autism. CTNND2 plays a role in the development of the nervous system. Some defects in this gene lead to impaired development and maintenance of neural circuits in the brain. These defects may affect cognitive function and appear to contribute to rare severe cases of autism in females.
Autism spectrum disorder (ASD) and autism refer to a group of complex disorders of brain development. These disorders are characterized by difficulties in social interaction, verbal and nonverbal communication, and repetitive behaviors. Autism affects about 1 in 68 children. Although much of the risk for autism is inherited (genetic variability explains around 70% of autism cases), environmental factors also contribute. More and more people are being diagnosed with ASD. In response to this trend, there is an increased effort to identify potentially modifiable risks (i.e., risk factors that can be controlled or modified). In recognition of the growing population of persons with ASD, Connecticut established the Division of Autism Services. The Division provides a range of services to children and adults with ASD and their families.
Autism is a common neuro-developmental disorder that affects four times as many males as females. This gender bias suggests that females are affected only by severe variations in autism genes that affect key developmental processes. To identify these possible candidate genes, scientists analyzed protein-coding genes in females with severe autism. They identified 18 candidate genes that have potentially harmful variants. CTNND2 is one of these genes. Employing an animal model used for studying human disease, the scientists discovered that loss of function of CTNND2 has harmful effects on the development and/or maintenance of synapses (the structure that permits a nerve cell to pass an electrical or chemical signal to another cell). These findings point to a critical role for the CTNND2 gene in the development of the nervous system and in autism.
