  Hydroxymethylcytosine (5hmC) methylation is known to be a possible epigenetic
mark impacting genome stability. In this paper, we address the existing 5hmC
measure $\Delta \beta$ and discuss its properties both analytically and
empirically on real data. Then we introduce several alternative
hydroxymethylation measures and compare their properties with those of $\Delta
\beta$. All results will be illustrated by means of real data analyses.
