Epic / Epigenetics (broader concept)

**What it means:** Epigenetics is the study of changes in gene **activity** that don't involve changes to the DNA sequence itself. Think of your DNA as a piano — the keys (genes) are always there. Epigenetics is like the sheet music — it tells the piano which notes to play and which to skip. The same piano, different music, depending on the epigenetic "sheet music." **Three main epigenetic mechanisms:** 1. **DNA methylation** (the "highlighter marks" — described above) 2. **Histone modification** — wrapping DNA around protein spools; looser wrapping = more active genes 3. **Non-coding RNA** — RNA molecules that regulate other genes **In MHS:** The episignature is one type of epigenetic biomarker. The broader field of epigenetics matters because it means there might be treatments that **modify** gene activity without changing the DNA sequence itself — potentially a gentler approach than gene therapy.