Researchers have for some time believed that autism spectrum disorder (ASD) – a neurological and developmental disorder that begins early in childhood and lasts throughout a person’s life, affecting how a person acts and interacts with others, communicates and learns – has genetic and environmental causes.
ASD is diagnosed behaviorally usually at before the age of four, but the causes of most cases have not yet been clearly identified. However, if a medical finding can be linked to future ASD symptoms, then medical observation might enable earlier diagnosis. The earlier the diagnosis, the better children respond to behavioral treatments.
Israeli and American researchers have now surprisingly concluded that some cases result from dyslipidemia – abnormal levels of fats in the blood.
The group of scientists – biomedical informatics specialists from Ben-Gurion University (BGU) of the Negev in Beersheba and Harvard University, the Massachusetts Institute of Technology and Boston Children’s Hospital in Massachusetts and Northwestern University in Illinois — link dyslipidemia to autism. They processed huge amounts of data about US children with ASD and discovered that some of them also had abnormal levels of fats in the blood.
Dyslipidemia was found to affect five percent of children with ASD. In comparison, one of the most common comorbidities of ASD is epilepsy, which affects between five percent and 30% of children with ASD.
The study, conducted by Dr. Alal Eran of the life sciences department at BGU along with American colleagues, has just been published in the prestigious journal Nature Medicine. Eran is also a member of BGU’s National Autism Research Center of Israel and affiliated with Boston Children’s Hospital and Harvard Medical School.
The team integrated whole exome sequencing (a genomic technique for sequencing all of the protein-coding regions of genes in a genome, which is also known as the exome) covering one percent of the human genome) with neurodevelopmental gene expression patterns, electronic health records and healthcare claims.
Since ASD is thought to arise during early brain development and because boys make up 80% of children diagnosed with the disorder, the researchers narrowed down the data by focusing on genes that function together during early brain development in a different way between males and females,
Focusing on mutations that are shared among multiple affected siblings of the same family and those that are different between affected and unaffected siblings, they found that many of them affect lipid regulation functions.
By analyzing the medical records of millions of children treated at Boston Children’s Hospital and cross-checking their data through health insurance claims, they discovered that dyslipidemia kept coming up. Dyslipidemia can be hereditary, and many more parents of children with ASD had been diagnosed with it than parents of children without ASD.
“Biomedical informatics,” noted Eran, “is a relatively new field whose advantages are becoming apparent. Analysis of large amounts of diverse data lead us to this exciting discovery of a previously unrecognized ASD subtype. Our discovery brings us a step closer to precision medicine for ASD.”