Six months of gender affirming hormone treatment modifies the methylome in the transgender population

The main objective was to carry out a prospective global CpG (cytosine-phosphate-guanine) methylation analysis before vs. after six months of gender affirming hormone treatment (GAHT), in a transgender population vs. a cisgender population. A global CpG methylation analysis was performed on 16 transgender people before vs. after GAHT and compared to 16 cisgender people, using the Illumina© Infinium Human Methylation 850k BeadChip. Global methylation was analyzed with the Partek® Genomics® Suite program (false discovery rate correction FDR p < 0.05; fold change ≥ ±2) by a 3-way ANOVA test comparing populations by group, assigned sex at birth and GAHT. We added six contrast interactions: trans men (before vs. after), trans women (before vs. after), cis men vs. trans women (before and after), and cis women vs. trans men (before and after).