Chronic bronchitis may be hereditary.
Preliminary studies of patients suffering wheezing bronchitis suggest that there is a higher prevalence of either asthma or bronchitis in recorded family medical histories.
Archives of Disease in Childhood
The first study to support the idea that certain types of bronchitis may be hereditary was published in the Archives of Disease in Childhood. Researchers from the Cardiothoracic Institute, Brompton Hospital in London set out to explore the possibility of a genetic basis of asthma and wheezing bronchitis.
The study examined the family histories of a group of 242 children between the ages of 1-12 years to measure the incidence of asthma or wheezing bronchitis in family members of children suffering from one or the other. The group contained 77 asthmatic children, 78 children suffering from wheezing bronchitis, and 87 control children. Though admittedly the results did not reach significance, the researchers did note that family history did seem to play a role in the children's risk of the respiratory illnesses and concluded that the tendency of wheezing bronchitis to run in the families of children with wheezing bronchitis supports the idea that wheezing bronchitis and asthma may be due to a common genetic defect. (Sibbald, 354)
The American Journal of Respiratory and Critical Care Medicine
The second study set out to explore the interaction between smoking and genetic factors in the development of chronic bronchitis. The study measured the disease cases and smoking habits of 44,919 twins over 40 and concluded that the heredity estimate for chronic bronchitis was 40% while smoking habits combined with genetic factors only accounted for 14%. The researchers concluded that this evidence supports the idea that genetic factors independent of smoking habits play a role in the development of chronic bronchitis. (Hallberg, 486)