A link between autism and genes regulating cholesterol shows an approach at studying subtypes of ASD

Autism, just like cancer and many other diseases, revolves around our genetics. Recently, researchers at Harvard have identified a subtype of autism that is associated with a cluster of genes which regulate cholesterol metabolism and neurodevelopment. This is exciting research because as we gain more insight into what is happening at the molecular level, we can begin studying how these mechanisms work pleiotropically.

Autism is four times more common in males than females, so this research team began by analyzing the patterns of gene expression related from two massive national brain banks, focusing on genes that work in pre- and post-natal neurodevelopment. They found a mutation that occurs more often in people with autism that regulated both neurodevelopment and fat metabolism. Together, the two data sets had over 30 million subjects. The researchers found that roughly 6.5 percent of people with autism (80,700 subjects with autism) also had abnormal lipid levels - around twice as much as people without autism. Mothers and fathers of children with autism were 16 and 13 percent more likely to have lipid abnormalities respectively. Of children with autism and siblings, children with autism were 76 percent more likely to have abnormal lipid profiles than their siblings. 

Among people with autism and abnormal lipid levels, comorbidities with other neurological disorders like epilepsy, ADHD, and sleep disorders were more common than people who had autism with typical lipid levels. This suggests that this could be related to neurodevelopment in general. This link also offers a molecular explanation to a closely related disorder Rhett syndrome. Additionally, between 50 and 88 percent of people with Smith-Lemli-Opitz syndrome, caused by defects in cholesterol synthesis also have autism. 

This study highlights the intricacy of our biology. As we learn more and more about how our brains work at a molecular level, we are better able to understand and manipulate or treat/regulate the way our brains function. Just as the field of oncology has been progressing over the past fifty years through targeted therapies on specific subtypes of cancer, our understanding of autism can progress too. Because the truth is, it all comes down to the fact that our biology is so complex. Autism, which is rooted in biology, is also complex. As we begin to examine the different types of autism, as we begin associating patterns of neurochemistry with patterns of behavior and symptoms, we can begin to improve available treatment.

Link to primary article: A multidimensional precision medicine approach identifies an autism subtype characterized by dyslipidemia