New Link Found Between Gene Mutation, Working Memory and Autism

Autism Spectrum Disorders (ASD) are a complex continuum of neurobiological conditions that overlap with ADHD symptoms in up to half of children with ASD. Children with ASD can be mistakenly diagnosed with ADHD if they struggle socially or have slow language development. The key to differentiating between the disorders is examining the symptoms’ root causes. Is it an executive function issue, or a missing developmental building block creating the problem?

New research concentrating on a mutation in one specific gene — the phosphatase and tensin homolog (PTEN) — is now one step closer to identifying hallmark signs of this complex brain disorder. Children with the PTEN mutation and autism often also have macrocephaly, or head enlargement. The researchers contrasted data from 17 PTEN-ASD children who had the enlarged head trait with data from three other groups: 16 participants with autism and macrocephaly, 38 children with only ASD, and 14 people with no disorder. They found that the children who had the PTEN mutation also had working memory trouble. This group processed information slowly, and showed difficulty retaining information in their short-term memory while working on a task.

Researchers used magnetic resonance imaging (MRI) to determine that these problems were a result of the PTEN mutation, which caused a malfunction preventing the full development in white matter. White matter allows the regions of the brain to communicate with each other. The breakdown of connections between different areas of the brain could help to explain why children have ASD. Scientists also fear that the PTEN mutation could make people more susceptible to developing cancer, since it impairs the body’s natural tumor suppressor. While they recommend screening kids as they grow older, it is important to note that there is no hard evidence that this mutation definitively raises cancer risk.

What the research does indicate is a new way to analyze autism-related difficulties. Children with ASD and the PTEN mutation comprise only 1% of the total population with the diagnosis, but this approach sheds new light on how to study all the autisms. First, look at the gene and identify what it does and how it impacts behavior, and then work on discovering treatments specific for that gene and it’s behavioral outcome. The researchers are hopeful that this new way of comparing the brain and behavioral characteristics of autism can help identify why learning problems occur for children with PTEN-ASD, and new ways to treat working memory difficulties with educational programs.