[Is there a genetic component in bronchial hyperreactivity in the human species?]

Whether a hereditary, genetic component of human non allergenic bronchial hyperresponsiveness exists in man is controversial. Therefore, the "Dutch hypothesis" that bronchial hyperresponsiveness is a risk factor of asthma and chronic bronchitis has not been validated by hard data, although it was put forward more than two decades ago. In some inbred strains of mice and rats, bronchial hyperresponsiveness to acetylcholine or serotonin is transmitted as a Mendelian monogenic trait or a polygenic one. Genetic studies of human bronchial hyperresponsiveness are difficult, if only because it is an ill-defined phenotype, and because acquired, inflammation-related bronchial hyperresponsiveness is at the forefront in airway diseases such as asthma. Studies of concordance in mono- and dizygotic twins, of distribution in the general population, and of familial inheritance suggest transmission from generation to generation of human bronchial hyperresponsiveness. This only applies to bronchial response to cholinergic agents because of the small number of studies done with other bronchial challenges. Furthermore, there is no agreement on the mode of transmission of this specific type of bronchial hyperresponsiveness. One hopes that combining genetic epidemiology with molecular genetics in the forthcoming years will result in a better understanding of genetic risk factors of human bronchial hyperresponsiveness.