Mothers with diabetes more likely to have autism-linked anti-fetal brain autoantibodies.

Autism spectrum disorder (ASD) is a neurodevelopmental condition that manifests in early childhood and is characterized by impairments in social communication and presence of stereotyped behaviours and restricted interests, with varying degrees of symptom severity and presentation. Approximately 23% of mothers of children with ASD produce speciﬁc patterns of autoantibodies to fetal brain proteins that have been detected in only 1% of mothers of typically developing children. However, the biological mechanisms underlying the development of ASD-speciﬁc maternal autoantibodies are poorly understood. Now, a study from researchers at UC Davis shows that mothers of children with autism and were diagnosed with metabolic conditions during pregnancy, particularly gestational and type 2 diabetes, were more likely to have anti-fetal brain autoantibodies in their blood compared to healthy women of children with autism. The team state that they found a three-fold increase in the prevalence of anti-fetal brain antibodies among the mothers of children with autism who were diagnosed with gestational diabetes or type 2 diabetes. The study is published in the journal Autism Research.

Previous studies show that the presence of these anti-fetal brain autoantibodies has been previously found to be specific to some mothers of children with autism and rare among mothers of children without autism. Earlier studies from the team showed that approximately 23% of women with a child diagnosed with autism had specific patterns of autoantibodies that target proteins highly expressed in the fetal brain. These autoantibody patterns were detected in only 1% of women who did not have children with autism. The finding, reported in 2013, was the first to identify a specific risk factor for a significant subset of autism cases, as well as a potential biomarker for drug development and early diagnosis. The current study shows that diabetic women were three times more likely to have anti-fetal brain autoantibodies, particularly those whose children’s autism fell on the severe end of the spectrum.

The current study investigated 227 mother/child pairs who are participants in the Childhood Autism Risk from Genetics and the Environment (CHARGE) Study, which examines the environmental and genetic causes of autism. Results show that autism-specific maternal autoantibodies were more prevalent among mothers diagnosed with diabetes, hypertensive disorders, or who were moderately overweight compared to healthy mothers. Data findings show that women with other metabolic conditions, such as high blood pressure and elevated body mass index (BMI) also had a higher prevalence of anti-fetal brain autoantibodies.

Results show that among the study participants, 145 mothers had children who exhibited symptoms of severe autism and of these mothers, those diagnosed with type 2 or gestational diabetes were nearly three times more likely to have the autism-specific anti-fetal brain antibodies, when compared with healthy mothers.

The team surmise that their findings show metabolic conditions are characterized by increased inflammation. They go on to add that as a number of studies have established links between metabolic conditions during pregnancy and neurodevelopmental conditions in children, it is also reasonable to presume that these conditions may alter the maternal immune tolerance to the fetus during pregnancy. For the future, the researchers state that women who are planning a pregnancy should be encouraged to achieve a healthier pre-pregnancy weight through changes in diet and physical activity, and if a mother was diagnosed with a metabolic condition to keep a closer watch of the baby’s development.

Source: UC Davis MIND Institute