Parenting a child who has autism is not an easy thing to do. While there are many genetic and environmental factors leading to this condition, your child’s and your cholesterol levels or the alteration in lipid blood could also be the reason behind this neurodevelopment dysfunction.
A new study published in the journal Nature Medicine–conducted by researchers from Harvard Medical School, Massachusetts Institute of Technology, and Northwestern University has identified the shared molecular roots between lipid dysfunction and autism through DNA analysis of brain sample.
These findings were then confirmed by examining the medical records of individuals with autism. The analysis showed that both the children with autism and their parents had pronounced alterations in lipid blood.
The results of the study raise many questions such as how do lipid alterations drive neurodevelopmental dysfunction like autism and could normalising lipid metabolism affect such disease outcomes? These new findings have set the stage for further studies to answer these questions.
What the researchers have to say about this study?
Senior investigator Isaac Kohane, chair of the Department of Biomedical Informatics in the Blavatnik Institute at Harvard Medical School says, ”Our results are a striking illustration of the complexity of autism and the fact that autism encompasses many different conditions that each arise from different causes–genetic, environmental or both.”
“Identifying the roots of dysfunction in each subtype is critical to designing both treatments and screening tools for correct and timely diagnosis–that is the essence of precision medicine,” added Kohane.
Autism is among the most complex heritable conditions. Thousands of gene variants, both rare and common, have been implicated in autism, likely through an intricate and not-well understood interplay between genetic and environmental factors–both before and after birth.
Also, read: Nosh on these 5 foods to reduce your cholesterol and keep your heart happy
The study findings not only underscore this complexity but also demonstrate the critical importance of defining the various subtypes of the condition and developing treatments that target subtype-specific anomalies.
How was the study conducted?
Achieving a level of specificity in the study of a vastly complex disorder such as autism is not easy. The researchers used a novel approach based on the interlacing of multiple layers of data, including whole-exome sequencing, patterns of protein expression, medical records and health insurance claims.
“Think of a Google map and how it overlays various types of information on top of one another–cities, streets, parcels, land use, electrical grids, elevations–for a more detailed representation. This is what we did with our data to get a complete view of genes that have multiple regulatory functions and are implicated in autism,” said Yuan Luo, who co-led the study with Alal Eran, a Harvard Medical School lecturer on paediatrics at Boston Children’s Hospital.
The research team started out by analysing patterns of gene expression from brain samples contained in two large national brain banks, focusing on genes that work in tandem during prenatal and postnatal brain development. Since autism is four times more common in males than females, they further focused on genes that had the largest male-to-female differences during development.
Within those, they aimed at exons–the protein-coding parts of genes–to seek out mutations that occurred more often in patients with autism. Through this, the researchers identified a previously unrecognize node of shared function–a cluster of exons regulating both neurodevelopment and fat metabolism.
How are autism and lipid dysfunction linked together?
To confirm whether the molecular link between autism and lipid metabolism was borne out in actual patients, the team turned to two vast clinical record repositories. In one that contained more than 2.7 million records of patients seen at Boston Children’s, including more than 25,000 children with autism.
The researchers identified notable lipid alterations in children with autism, including changes in levels of their bad cholesterol (LDL), good cholesterol (HDL) and triglycerides.
The other dataset contained medical records of more than 34 million individuals seen at multiple U.S. medical institutions. Of those, more than 80,700 individuals had diagnoses of autism. About 6.5% of those who had an autism diagnosis also had abnormal lipid levels. Individuals with autism were nearly twice as likely to have abnormal lipid tests results as those without autism.
There was a pronounced familial link
Mothers with lipid abnormalities were 16% more likely to have a child with autism than mothers without lipid abnormalities. The risk of having a child with autism among fathers with lipid abnormalities was 13% greater than in males with normal lipid levels. And within families with more than one child, children diagnosed with autism were 76%, more likely to have abnormal lipid profiles than their siblings.
Among individuals with autism and abnormal lipid levels on their blood work, conditions such as epilepsy, sleep disorders and attention deficit hyperactivity disorder were markedly more common than among those without elevated lipid levels. This finding suggests dyslipidemia may alter neurodevelopment in general. Individuals with autism and dyslipidemia were also more likely to have certain hormonal and metabolic conditions including anaemia, hypothyroidism and vitamin D deficiency.
Also, read: Pregnant women, listen up! Prenatal factors are linked to increased risk of autism
The study concluded that…
A molecular explanation to the well-established observation that a mutation in a gene is involved in cholesterol metabolism is also found in people with Rett syndrome, a neurodevelopmental disorder also related to autism. Another striking observation that may be explained by the newly found link is that between 50 and 88% of children born with Smith-Lemli-Opitz syndrome, caused by a defect in cholesterol synthesis, also have autism.
According to the researchers, their approach–based on integrating multiple data modalities — could be adapted to other similarly genetically complex conditions such as the ability to identify disease subtypes in cancer.
While you cannot do anything about the genes, you can certainly control your cholesterol levels to reduce the risk of autism and other neurodevelopment dysfunction in your offspring.
Get latest updates on health and wellness along with Health News