Harvard study suggests subgroups of children with autism share health problems; separate Autism Speaks study promises further insights.
A Harvard Medical School analysis of electronic medical records suggests that some children with autism fall into one of three distinct subgroups based on common medical issues.
- Those in the first group have seizures, or epilepsy.
- Those in the second have health issues that affect multiple body systems such as seizures combined with GI disorders and/or hearing and cardiac problems.
- Those in the third have psychiatric disorders such as bipolar disorder, attention deficit and hyperactivity disorder (ADHD) or obsessive compulsive disorder.
These groups may reflect distinct types of autism and might even point to different genetic and environmental risk factors, the researchers conclude. Their report appears in the February issue of the journal Pediatrics.
"Doctors who take care of patients with autism need to be aware of the associated medical concerns, and this report shows how some of the medical problems might cluster together," comments Paul Wang, Autism Speaks senior vice president for medical research. (Dr. Wang was not involved in the Harvard study.) "Previous research from the Autism Speaks Autism Treatment Network showed that some behavioral symptoms of autism likewise appear to cluster with certain medical complications," he adds. "Identifying these clusters of symptoms will help us to better understand autism's underlying biology and help us to develop individualized treatment approaches."
The Harvard researchers used bioinformatics techniques to analyze health-insurance codes in more than 5,000 medical records from Boston Children's Hospital. However, the study had a number of limitations. For instance, it lacked a control group of children who didn't have autism. As a result, the researchers couldn't determine whether the symptom clusters they found were specific to autism.
Another limitation was that the study was centered at one medical center, which could skew results. Boston Children's, for example, is renowned for treating epilepsy. So it might draw an unusually high number of children who have seizures.
Autism Speaks is currently funding another study that should provide more clarity. It will analyze a similarly large database of electronic medical records to look for patterns of medical conditions among children with autism. However, it will do so across a number of hospitals in different states. And it will include control groups of children without autism. The study will also look for immune-related conditions such as infections, allergy, asthma, auto-immune disorders and reactions to vaccination.