Scientists say they have found a link between autism and proteins in blood, allowing for a new test that could diagnose the disorder better than ever before.

Led by Dr Naila Rabbani from the University of Warwick, the team’s test involves searching for damage to proteins in blood via blood and urine tests. A study describing the findings, published in Molecular Autism, said this could be used to detect autism spectrum disorders (ASD).

"Our discovery could lead to earlier diagnosis and intervention," Dr Rabbani said in a statement.

"We hope the tests will also reveal new causative factors. With further testing we may reveal specific plasma and urinary profiles or 'fingerprints' of compounds with damaging modifications. This may help us improve the diagnosis of ASD and point the way to new causes of ASD."

In the study, conducted in partnership with a number of other institutions, 38 children (29 boys and nine girls) were selected who were diagnosed with ASD. A control group of 31 healthy children (23 boys and eight girls) were also selected.

The team took blood and urine samples from the children, aged between five and 12, and found that there were chemical differences between the two groups. Specifically, they found that children with ASD had higher levels of an oxidation marker called ditryosine (DT), and certain sugar-modified compounds called "advanced glycation endproducts" (AGEs).

Using an algorithm to sift through the data, the team said their results were better than any method currently available to detect ASD, being up to about 90 percent accurate. This could be used not only to detect existing causes of ASD, but new ones too.

The study was with quite a small group, so further testing will be required to confirm the findings. But if that’s the case, the test could prove extremely useful, allowing researchers to see if the disorder will develop further in an individual, and also see if treatments are working.

ASD can cause a wide range of behavioural problems, such as compulsive behaviour, anxiety, speech problems, and more. About 1 percent of the world has ASD, which can cause serious complications with employment and day-to-day life. Detecting it early can be hugely beneficial, making studies like this very important.