Six months of gender affirming hormone treatment modifies the methylome in the transgender population. 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. Overall design: 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).