Abstract
Epigenomics, the study of modifications to genetic material that do not alter the
underlying DNA sequence, is generating increasing interest as a means to help clarify
disease pathogenesis and outcomes. Although genome-wide association studies have identified
several potential candidate genes that may be implicated in primary biliary cholangitis
(PBC) and primary sclerosing cholangitis (PSC), it is estimated that these genes explain
less than 20% of the heritability of these diseases. Thus, to date, the origins of
“missing heritability” for PBC and PSC remain elusive. The epigenome may provide a
potentially elegant solution to this phenomenon, as it can be modified by both internal
and external exposures (coined the “exposome”). This may explain differences in disease
presentation, treatment response, and rates of progression between individuals. Epigenetic
changes may also provide a framework for discovering potential biomarkers for diagnosis
and screening of PBC and PSC. Importantly, because the epigenome is modifiable, it
may also highlight novel pathways for therapeutic discovery and interventions of these
diseases.
Keywords
cholestatic liver disease - epigenetics - primary biliary cholangitis - primary sclerosing
cholangitis
