Article Text

Download PDFPDF
Genes and environment in asthma: a study of 4 year old twins


BACKGROUND Although the genetic and environmental factors of asthma have been investigated in adolescence and adulthood, no previous studies have focused on the early development of asthma.

AIMS To test, in a large sample of 4 year old twins, the hypotheses derived from the literature on adolescents and adults that genetic influences are substantial and shared environmental influences are modest.

METHODS The sample consisted of 4910 twin pairs who were born in England and Wales in 1994 and 1995. Data on asthma status were obtained from the twins' parents by postal questionnaire.

RESULTS Univariate parameter estimates derived from model fitting were 68% heritability, 13% shared environment, and 19% non-shared environment.

CONCLUSIONS Our findings suggest that asthma is highly heritable in 4 year olds, whereas shared environmental influences are not statistically significant.

  • twin studies
  • risk factors
  • asthma
  • genetics

Statistics from

Request Permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.