I am analyzing microarray data of patients followed from birth up to an age of 3 years. The samples were taken at various age points for each child.
I want to identify non constant gene expression over time within these children, so genes that are differentially expressed over time.
For this I have applied a mixed effects model with splines(df=3) in limma adjusting for sex as a covariate.
X <- ns(age, df=3)
The topTable function results in various differentially expressed genes, I have set the coef parameter to coef=1:3, including the columns X1,X2 X3.
My question is how are the log2foldchanges in the result table of topTable() interpreted?
Many thanks in advance