1. Genetic influence on the age at onset of asthma: A twin study
Simon Francis Thomsen, MD, PhD, David Lorenzo Duffy, MD, PhD, Kirsten Ohm Kyvik, MD, PhD, MPM, Vibeke Backer, MD, DMSc 
Journal of Allergy and Clinical Immunology 
Volume 126, Issue 3, Pages (September 2010)
DOI: /j.jaci
Copyright © 2010 American Academy of Allergy, Asthma & Immunology Terms and Conditions

2. Fig 1
Risk of asthma in the co-twin of an affected twin. DZ-os, Opposite-sex dizygotic twins; DZ-ss, same-sex dizygotic twins; MZ, monozygotic twins.
Journal of Allergy and Clinical Immunology  , DOI: ( /j.jaci )
Copyright © 2010 American Academy of Allergy, Asthma & Immunology Terms and Conditions

3. Fig 2
Correlation between age at onset of asthma within twin pairs. The black dots are pairs in which both have asthma; the gray circles are pairs in which 1 twin has asthma. The contours are the Dabrowska estimates of the bivariate survival function.
Journal of Allergy and Clinical Immunology  , DOI: ( /j.jaci )
Copyright © 2010 American Academy of Allergy, Asthma & Immunology Terms and Conditions