Blood Tests for the Detection of Autism - Help Week

By Anna Swann-Pye

Diagnosing autism is a difficult task. A definitive definition is hard to come by – so hard, in fact, that the term ‘Autism Spectrum Disorder‘ has been substituted in place of all the preexisting definitive categories (Autism Disorder, Asperger’s Disorder and Pervasive Developmental Disorder) in the new Diagnostic and Statistical Manual of Mental Disorders (DSM V). Typically a diagnosis requires an in-depth assessment of performance tasks in a clinic – a process that can be exhausting for both doctor and patient.

Photo by helpingting.

However, this extensive behavioral testing might be in the process of change. According to PLOS ONE, the online science journal, Boston Children’s Hospital has come up with some new substantial findings. They have, according to Time magazine’s website, recently described a new experimental test that detects developmental disorder by looking at blood. This test, which has already been licensed to a company, SynapDx, seems to predict autism relatively accurately and may be used clinically in the near future.

But what is the test detecting? “Scientists believe that autism has some genetic basis, based on genes that have been associated with the disorder and the fact that the disorder runs in families” writes Laura Blue for In order to find the genetic disparities, children with diagnosed Autism spectrum disorder were measured against children without.

“There are a lot of different mutations involved,” says Isaac Kohane, pediatric endocrinologist and computer scientist at the Children’s Hospital, to Time.

PLOS ONE cites one of the major genetic differences:

[We would suggest] a link between autism and immune dysfunction and that specific cellular phenotypes or activation status of immune cells may be altered in autism. Autism is also associated with a variety of co-existing symptoms including seizures, sleep disturbances and gastrointestinal problems many of which may be influenced by altered immune function.

But immune deficiency is not the only difference that can be cited. Some of the disparities can be seen in relative immune functions, while others can only be recognized by comparing learning techniques.

“The fact that not all kids have both…spoke to the genuine heterogeneity of the disease,” continues Kohane, “in that respect, autism is beginning to look a lot like what the cancer biologists are telling us about breast cancer or lung cancer. There may be hundreds of different molecularly defined cancers, which each have their own specific optimal treatment.”

What this means is that testing ASDs through blood samples can be a tricky process. There are a number of variables that need to be individually recognized and taken into account.

“Using microarrays to analyze patterns of gene activity in blood samples from 258 patients and 158 people without ASDs, Louis Kunkel, director of Genomics program at Children’s, and Isaac Kohane, director of the Informatics program, have identified a genetic ‘signature’ that consists of 245 genes uniquely switched on or off in the people with ASDs,” writes Michelle Pflumm for the Boston Children’s Hospital website.

The next question, though, is whether or not these blood tests can be used to identify ASD in children before they show visible signs. If it were possible to detect Autism when a child is young, there would be a far greater chance of intervention.

In their story about Charlie Lamb, a boy who’s Autism was detected at age 2, Time suggests the effectiveness of early tests.

Charlie began a comprehensive autism treatment that seems to work well for children as young as 18 months. Although none of the children were ‘cured’, those who received the treatment made major leaps in IQ scores, language use, and task efficiency.

According to the article:

Charlie Lamb was among the 24 children in the treatment group. Though the first few sessions were hard, Charlie soon began to enjoy the playful therapy and made steady progress in speech and behavior. Now 5½, he attends a special preschool and continues to work with therapists on social skills and language. The Lambs expect that Charlie will ultimately attend a regular school. “His autism is subtle,” says Susan Lamb. “Most people say they can’t tell.” But like most children with autism, Charlie suffers from anxiety and is especially vulnerable in unfamiliar situations.

So, if this blood test were to be deemed accurate enough to use clinically with some regularity, it may prove to be an incredibly useful test. Unfortunately, it’s not quite there yet.

The test is still in very early stages of development. Although the tests are about 70 percent accurate, Kohane stresses that there are still too many false positives to rely on it completely. But, if results are confirmed and trials continue to come up with relatively positive results, we may have a reliable blood test for autism in the next few years.