Table 2.

Epigenetic implications in Postpartum Depression.

S. No.	Genes involved	Epigenetic Implications	References
1	Oestrogen-mediated DNA methylation: HP1BP3 and TTC9B	Elevations in oestrogen mediated DNA methylation change were observed in PPD diagnosis of women within four weeks postpartum and genes HP1BP3 and TTC9B were reported as significant biomarkers.	(Guintivano et al., 2013)
2	HSD11B2, CRHR2 and SLC6A4	Positive associations between maternal stress and HPA axis gene expression (HSD11B2, CRHR2, and SLC6A4) were observed in a human study involving 50 participants.	(Chen et al., 2014)
3	OXTR	Being depressed both throughout pregnancy and after delivery is connected to considerably increased OXTR methylation in exon 3. When depression occurs for a longer duration, OXTR gene expression may be inhibited.	(King et al., 2017)
4	CYBA and PRKCZ	The umbilical cord blood (UCB) of mothers who experienced depression in the middle of their pregnancy had lowered methylation at the CYBA gene (cg08667740) and PRKCZ (cg22868225) according to research by Viuff and colleagues. Inflammatory responses are influenced by this gene.	(Viuff et al., 2018)
5	FOXp3, CLOCK, CRY1, PER1 and PER2	A study that involved 44 pregnant women looked into the candidate genes FOXp3 (essential for the function of regulatory T-cells and immune system homeostasis), CLOCK, CRY1, PER1, and PER2 (responsible for circadian rhythm), and found that depressed women had hypermethylation of these genes. The same study showed hypomethylation of CRY1, PER1, and PER	(Buoli et al., 2019)