1 / 8

Heritability and environmental effects for self-reported Otitis Media: A twin study from Denmark

Heritability and environmental effects for self-reported Otitis Media: A twin study from Denmark. Jacob v. B. Hjelmborg Department of Biostatistics, University of Southern Denmark Steen Fibiger Department of Public Health, University of Southern Denmark University Library of Southern Denmark

paytah
Download Presentation

Heritability and environmental effects for self-reported Otitis Media: A twin study from Denmark

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Heritability and environmental effects for self-reported Otitis Media: A twin study from Denmark Jacob v. B. Hjelmborg Department of Biostatistics, University of Southern Denmark Steen Fibiger Department of Public Health, University of Southern Denmark University Library of Southern Denmark Axel Skytthe The Danish Twin Registry, University of Southern Denmark Corrado Fagnani Italian National Institute of Health, Rome, Italy

  2. Subjects and Questionnaire A paper and pencil questionnaire was sent to a population-based cohort of 46,418 twins, who had participated in earlier questionnaire studies and were born 1931 to 1982 in Denmark. The questionnaire was a 20 page A4 booklet with 119 main questions concerning: functioning, activity, disability, health, diseases, education, occupation, weight and length; tobacco smoking, alcohol consumption, family relations and children; fertility, thoughts and emotions (Skytthe, et al., 2006).

  3. Question to screen the twins for middle ear infections: Did you as a child have periods with middle ear infections (Otitis Media) or pain in your ears?

  4. Table I: Summary counts and incidence rates of middle ear infections by zygosity and gender *MZ = Monozygotic twins, SSDZ = Dizygotic twins from same-gender pairs, OSDZ = Dizygotic twins from opposite-gender pairs, (M) = Males, (F) = Females **In parentheses are 95% confidence intervals adjusted for multiple comparison

  5. Table II: Numbers of complete twin pairs, concordant pairs, and discordant pairs, along with incidence rates, probandwise concordance rates, and tetrachoric correlations for middle ear infections, separately for monozygotic (MZ) and same-gender dizygotic (SSDZ) twin pairs, males and females *In parentheses are 95% confidence intervals adjusted for multiple comparison

  6. Table III: Genetic and environmental proportions of variance for middle ear infections, as estimated under the best-fitting model. A = Additive genetic factors C = Common (shared) environmental factors E = Unique environmental factors *In parentheses are 95% confidence intervals adjusted for multiple comparison

  7. Conclusion: The present study showed that about 30 % of the Danish twins reported experience with middle ear infections. Additive genetic and unique environmental factors explained best the observed concordance patterns. Heritability estimates for male/females were 0.59/0.53. Conclusion Thank you for your attention

  8. Refused, and Fagnani’s comments: It is true that phenotypic correlations between ear infections and speech problems and between ear infections and slow reading were low. The only appreciable correlation was between speech problems and slow reading, but the way these two variables are measured was considered too crude. Reviewer 1 also stated that only the heritability of ear infections might have some value, having to do with the heritability of otitis media.It should probably be recognised that low phenotypic correlations among the targeted traits as well as poor measures of these traits will make very difficult to publish a multivariate study. Following reviewer 1, we could reduce the study to a simple univariate analysis of ear infections.

More Related