Heritability estimates
Heritability, which is the proportion of variance in a particular trait
(i.e. recurrent wheeze, asthma) accounted for by genetic factors was
estimated using the Dsquared function in the modEvA package, which
calculates the amount of deviance accounted for by a generalized linear
model.(36) As above, this analysis included sex and the 3 first PCs as
covariates.