@article{6d29308291344e5fac5e370933281020,
title = "A quantitative genetic analysis of intermediate asthma phenotypes",
abstract = "AIM: To study the relative contribution of genetic and environmental factors to the correlation between exhaled nitric oxide (FeNO), airway responsiveness, airway obstruction, and serum total immunoglobulin E (IgE). METHODS: Within a sampling frame of 21,162 twin subjects, 20-49 years of age, from the Danish Twin Registry, a total of 575 subjects (256 intact pairs and 63 single twins) who either themselves and/or their co-twins reported a history of asthma at a nationwide questionnaire survey, were clinically examined. Traits were measured using standard techniques. Latent factor models were fitted to the observed data using maximum likelihood methods. RESULTS: Additive genetic factors explained 67\% of the variation in FeNO, 43\% in airway responsiveness, 22\% in airway obstruction, and 81\% in serum total IgE. In general, traits had genetically and environmentally distinct variance structures. The most substantial genetic similarity was observed between FeNO and serum total IgE, genetic correlation (rhoA) = 0.37, whereas the strongest environmental resemblance was observed between airway responsiveness and airway obstruction, specific environmental correlation (rhoE) = -0.46, and between FeNO and airway responsiveness, rhoE = 0.34. CONCLUSIONS: Asthma is a complex disease characterized by a set of etiologically heterogeneous biomarkers, which likely constitute diverse targets of intervention.",
keywords = "Adult, Asthma, Environmental Exposure, Female, Humans, Immunoglobulin E, Male, Phenotype, Questionnaires, Respiratory Function Tests",
author = "Thomsen, \{S F\} and Ferreira, \{M A R\} and Kyvik, \{K O\} and M Fenger and V Backer",
year = "2009",
doi = "10.1111/j.1398-9995.2008.01850.x",
language = "English",
volume = "64",
pages = "427--30",
journal = "Allergy",
issn = "0105-4538",
publisher = "Wiley-Blackwell Publishing Ltd",
number = "3",
}