Genetic test for autism?

The identification of a gene involved in autism could lead to a new test for children at risk of developing the condition, French researchers say. The scientists, based at the company IntegraGen SA, have shown that variations in a gene called PRKCB1 are 'strongly associated' with autism. The finding, published in the journal Molecular Psychiatry, could help explain how some of the characteristics of the disorder develop, say the team.

Autism is a lifelong developmental disability that typically appears during the first three years of life. The disorder affects social and language skills, and the way in which a child relates to people, objects and events. Autism often runs in families, suggesting that it has a genetic basis, although it is thought that the combined effects of at least ten different genes are involved. Scientists at IntegraGen say they have used a novel method to identify 12 regions of the human genome that might harbour such genes.  

The scientists studied 116 families in which at least one member had autism, and found that a region on chromosome 16, containing the PRKCB1 gene, appeared to be linked to the condition. The PRKCB1 gene makes a substance called protein kinase C beta 1, which is key to the communication between two sorts of cells found in the cerebellum area of the brain. Previous research has shown that people with autism have a decreased number of both these types of cells, which are called granule and Purkinje cells. 'This is the first time that the protein PRKCB1, and the brain functions it is involved with, have been associated with autism', said team leader Jorg Hager.

The company plans to use its knowledge of PRKCB1 and three other genes that influence a person's susceptibility to autism to develop a risk assessment test for the condition. It aims to launch the test in 2006, and hopes that it will be used to help confirm diagnoses, and also to assess the risk of autism in children too young to show symptoms. However, UK autism expert Sir Michael Rutter, of the Institute of Psychiatry told BBC News Online that a genetic test for the disorder would not necessarily be helpful, since not everyone who had the gene variants responsible would develop severe autism. But he added that 'the real potential of this research is that it can, in conjunction with other research, lead to an understanding of what the disease processes are. In turn, that could lead to new treatments'.