Genetic test developed to predict the risk of autism

A genetic test capable of predicting a person's risk of Autism Spectrum Disorders (ASDs), with an accuracy greater than 70 percent, has been developed by researchers.

'This test could assist in the early detection of the condition in babies and children and help in the early management of those who become diagnosed', said lead researcher Professor Stan Skafidas, director of the Centre for Neural Engineering at the University of Melbourne, Australia.

ASDs, such as autism or Asperger's syndrome, are a group of developmental disabilities characterised by abnormal social interaction, impaired communication and repetitive behaviours. The severity of these symptoms varies greatly between people with a disorder.

The disorders can run in families, indicating a genetic component may be involved. Previous studies have identified variants in certain genes that are associated with increased risk of ASDs, but no single gene has been found to act as an accurate genetic test.

In a study published in the journal Molecular Psychiatry, scientists screened over 7,000 patients and unaffected relatives and identified 237 genetic markers that increase or decrease the likelihood of a person having an ASD. By assigning a positive score to each risk marker and a negative score to each protective marker, the authors were able to generate an overall score for each patient, with a higher score denoting a greater risk.

Although approximately one in 150 children in the USA have an ASD, making this condition relatively common, ASDs are often undiagnosed in the early stages. A recent study by the US Centers for Disease Control and Prevention (CDC) estimates an average age at diagnosis of four-years-old.

'Early identification of risk means we can provide interventions to improve overall functioning for those affected, including families', said Dr Renee Testa, a clinical neuropsychologist from University of Melbourne and Monash University and a co-author of the paper.

The researchers found that applying the test to patient and control samples allowed them to predict ASD diagnosis with an accuracy of 72 percent in people of central European descent. They next plan to assess the accuracy of the test by monitoring children who have not yet been diagnosed in an extended study.