Building Block to a Cure

Some forms of autism may have a biological basis not originating from malfunctioning of the brain [bold added]:

WHAT causes autism is a mystery. One theory is that a phenomenon called the cellular-danger response lies at the root of it. The CDR makes cells put their ordinary activities on hold and instead switch on their defence systems, in reaction to high levels in the bloodstream of chemicals called purines. These are important and widespread substances: ATP, a molecule that shuttles energy around cells, is a purine; so are half the “genetic letters” in DNA. Cells under viral attack tend to shed them. Too many of them in the blood can thus be a signal of viral infection. In that case activating the CDR makes perfect sense. But studies have shown that people with autism (and also those with some other brain conditions, such as schizophrenia) often seem to have chronic CDR. The purine signal has somehow got stuck in the “on” position.

Why this happens is obscure. But it has occurred to Robert Naviaux of the University of California, San Diego, that once the signal is stuck in this way, chronic CDR might, by subverting the function of crucial brain cells, be the immediate cause of the symptoms of autism. In a series of experiments, the latest of which has just been published in Translational Psychiatry, he makes a plausible case that this is exactly what is happening—and he also illuminates a route to a possible treatment.

Experiments showed that inducing CDR in mice caused the mice to show symptoms of human autism, i.e., "fear of strangers, fear of novelty and poor co-ordination." Dr. Naviaux was able to reverse the symptoms in the mice by using a powerful drug, suramin, that counters the cellular-danger response. (However, suramin has damaging side-effects that make it unsuitable for long-term human use.)

We're miles away from a safe cure for autism, if one even exists, but Dr. Naviaux' work with purines is a significant step in researching a condition that has afflicted thousands of patients and their families.

Note: Robert Naviaux is an expert on mitochondrial disease and its possible connection with childhood autism.