Laird Harrison

October 26, 2011

October 26, 2011 (Honolulu, Hawaii) — Children born with double take-offs in their lower airways may also have autism spectrum disorders (ASD), according to a study presented October 25 here at CHEST 2011: American College of Chest Physicians Annual Meeting.

The study could shed light on genetic components to the disorders, said Barbara Stewart, MD, a pediatric pulmonologist at Nemours Children's Clinic in Pensacola, Florida, who presented the study on patients with the unusual airway formation. "Every single one has autism or [ASD]," Dr. Stewart told Medscape Medical News.

No other research has found a 1:1 correlation between ASD and a feature of anatomy.

Dr. Stewart made the discovery while examining patients referred to her for persistent coughs. Bronchoscopy revealed that several patients had divisions in take-offs, which Dr. Stewart calls "doublets." All these patients had ASD, and all her patients with ASD had the doublets.

For the study, Dr. Stewart examined a sample of 49 patients. She acknowledged that this is a small number, and that future research needs to be done. However, if the findings are borne out, they could lead to a better understanding of what causes ASD.

Dr. Stewart said it is possible that the doublets cause more airway resistance — these patients tend to be short of breath. However, she does not think that these patients' breathing problems could be enough to cause any neurological damage that might lead to autism. "I think the whole thing occurs embryologically," she said.

This is the first finding that correlates anatomy of the respiratory system to ASD, but it is not the first anatomical finding, Steven P. Cuffe, MD, from the University of Florida at Jacksonville, told Medscape Medical News.

"The central nervous system is thought to develop abnormally in children with autism," he said. One recent study found that children younger than 2 years have a larger brain volume, and that this continued at follow-up at age 4 years, he said.

Another study showed that many children with autism have distinct facial characteristics, which suggested that these alterations occurred during gestation, he said.

"The report that children with autism seen at a pulmonary clinic for complaints of cough showed abnormal development of the lower airway provides more evidence of problems with organogenesis in children with autism," Dr. Cuffe concluded.

However, he pointed out that the population in Dr. Stewart's study is not only small, it is "highly selected." No one has investigated to see whether autistic children without respiratory symptoms also have airway doublets.

Still, Dr. Stewart said she hopes that the finding will provide some reassurance to parents who worry that they might have caused their children's autism. "I think it takes some of the pressure off parents," she said. "Autism is not something they did. It just happened."

Dr. Stewart and Dr. Cuffe have disclosed no relevant financial relationships.

CHEST 2011: American College of Chest Physicians Annual Meeting: Abstract 388A. Presented October 25, 2011.


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