Fig. 4

Dendrogram and heat map of the methylation profile in the analysed samples. Dendrogram of the nine samples demonstrates a clustering of samples 4–6 (FXS1 UT and the two different 5-azadC treatments, respectively) and 7–9 (FXS2 UT and the two different 5-azadC treatments, respectively), as expected (a). The distance between sample 1 (WT2 UT) and samples 2 and 3 (WT1 UT and WT1 T1, respectively) and the similarity between samples 2 and 3 can be explained by intrinsic difference and similarities between different cell lines. The closeness between sample 1 (WT2 UT) and 4 (FXS1 UT) confirms the observations by Alisch et al. [15]. Heat map of the methylation profile of randomly sampled loci of all analysed samples shows that samples from the same cell line type clustered together (b). It is possible to observe some changes in the methylation profile after treatment with 5-azadC that do not reach statistical significance (p > 0.05)