THE STORY BEHIND MATERNAL AUTOANTIBODY RELATED AUTISM (MARA)

Judy Van de Water

07/14/2022


AUCD's network of Intellectual and Developmental Disability Research Centers (IDDRCs) consists of 16 Centers. Fifteen Centers currently receive funding from the Eunice Kennedy Shriver National Institute for Child Health and Human Development (NICHD). IDDRCs contribute to the development and implementation of evidence-based practices by evaluating the effectiveness of biological, biochemical, and behavioral interventions; developing assistive technologies; and advancing prenatal diagnosis and newborn screening.

The immune response is designed to fight infections. Antibodies play a key role in our immune system by recognizing infections and germs and destroying them. Sometimes antibodies can mistakenly attack proteins or tissues from a person’s own self. These self-recognizing antibodies are called autoantibodies.

In humans during pregnancy, the developing fetus relies on the mother’s antibodies to protect it from invading bacteria and viruses. Most of the time, these antibodies are helpful in protecting the fetus. However, we have found evidence for certain ‘bad’ autoantibodies that attach to proteins in the developing baby’s brain. We do not know why or how these autoantibodies are produced. We do know that these autoantibodies attach to 8 proteins that are important in the development of neurons in the brain. We found that 23% of mothers of children diagnosed with autism had some combination of these autoantibodies, while less than 1% of mothers whose children did not have autism had them.

The next step was to develop better technology to detect these autoantibodies and test for Maternal Autoantibody Related Autism (MARA).  A most recent study at UC Davis MIND Institute utilized this new technology to examine specific patterns of these autoantibodies during pregnancy and their effect on the child. In their sample, they found that all 8 patterns of these antibodies were associated with an outcome of autism in the child. The most common pattern of autoantibodies made it 16 times more likely for an autism diagnosis in the child. This pattern was not found in the control sample of mothers. They extended these findings by identifying several specific patterns that are linked to autism with intellectual disability.

Researchers at UC Davis Mind Insitute have also worked to specifically investigate what these autoantibodies are doing to the developing brain. These types of studies are not possible in humans, so we use animal models that have autoantibodies like those found in humans.  Using these rat and mouse models, we have found changes in the way the brains develop, the overall size of the brain, and see changes in their behavior. This work helps us understand how the antibodies affect brain development.

In summary, testing for these MARA autoantibody patterns can be used to assess the likelihood of a child having autism. This will allow families to prepare for supports and services that their child may need sooner. By identifying specific strengths and challenges associated with MARA, they hope this work will also aid in the development of specific interventions for children diagnosed with MARA.

 

The story behind Maternal Autoantibody Related Autism (MARA)