Like blue eyes, connected earlobes, and the ability to roll your tongue, scientists think, the uncomfortable chest constriction of an asthma attack might pass genetically from parent to offspring. Recently, researchers from Boston found more evidence for a parental link to the disease, pointing to the father.

When Harvard University scientists studied airway constriction in 1,041 children with asthma ages 5 to 12 years old, they found that the father was more closely linked to the inflammatory condition than the mother, despite maternal links in previous studies. To get their results, the researchers repeatedly tested the children's lung capacity after they inhaled methacholine, a lung-constricting drug that induces an asthma attack. Over an average of 4½ years, the researchers tested the children, comparing the drug's effect on each child with the asthma histories of fathers and mothers.

Asthmatic children with two asthmatic parents had the strongest methacholine reaction, a tightening of the lungs called airway hyperresponsiveness. Children whose fathers had asthma also had a hyperresponsive airway constriction, but the researchers did not find this association between asthmatic children and asthmatic mothers.

"In some studies, having a mother with a history of asthma doubles the risk of subsequent childhood asthma, independently of other risk factors like smoking, allergy exposure, and premature birth," says study author Benjamin Raby, a professor of medicine at Brigham and Women's Hospital and Harvard Medical School. "However, most of these studies have looked at very young children [less than 5 years old]. In several of the studies that look at older children [5 years old or more], there actually appears to be a strong effect from the father as well."

In addition to age, Raby's study is different because it compared the severity of the disease with the parents' asthma history.

"In this study, we measured the airway responsiveness [airway twitchiness] and found that, here, the children with a paternal history of asthma had more twitchy airways," he says.

Finnish researchers may have found a gene that passes asthma from parent to child called GPR 154. Since GPR 154 is on a nonsex chromosome, one copy of the gene is passed to the child from each parent. However, sometimes these types of genes don't activate. If the mother's copy of this gene doesn't activate, it may explain the link between fathers and asthma.

While this study, out in the September issue of the American Thoracic Society Journal, won't provide any new treatments for asthma in the short term, the research does give scientists a better understanding of the disease.

"By knowing that the father's asthma history is important for the development of airway twitchiness, we can better focus our attention on the father's genes when studying this particular characteristic of asthma," says Raby. "In the long run, we hope to identify the genes that contribute to the development of asthma, so as to develop new treatments tailored to these genes."

To find out more: Check out the U.S. News Allergy & Asthma Center for more information.