People with autism spectrum disorders and people with intellectual disabilities have mutations in the SHANK2 and IQSEC2 genes, scientists from Germany and Australia report in two independent papers in the Nature Genetics weekly.
Autism is a developmental disability that most often manifests itself in the first three years of life as a result of a neurological disorder, i.e. abnormalities in the development and function of the brain. The degree of impairment can vary greatly, hence the term autistic syndrome or spectrum disorder, ranging from mild to very severe.
Autism and its spectrum disorders, according to statistics, occur in one in 500 people four times more often in boys than in girls, it is the third most common developmental disability – more common than Down’s syndrome. Children and adults with autism have problems with communicating in a group, performing joint activities, disorders make it difficult for them to communicate with others. Patients may make repetitive body movements, show unusual reactions to people, and often become attached to objects and resist changes in routine.
Mental retardation, commonly known as developmental delay, is a more common form of neurological disorder that affects one in 50 people.
Earlier studies have shown that genes involved in synaptic function, i.e. connections between nerve cells, influence the development of autism – which proves how important the proper structure of neuron connections and signal transmission between them is for the development of linguistic, social and cognitive abilities.
Gudrun Rappold and colleagues from Heidelberg University examined 580 patients with mental disorders, including the autistic spectrum, and found mutations in the SHANK2 gene in several of them, which encodes a protein that plays a very important role in maintaining the normal structure of nerve connections.
On the other hand, Jozef Gecz with a team from the University of Adelaide observed mutations in the gene encoding the IQSEC2 signal protein in four unrelated families with mental disorders. (PAP)