Serotype (AAV Serotype)

**What it means:** AAV isn't a single virus — it's a family of related viruses, each called a **serotype**. Different serotypes have different **tissue preferences** — some are better at reaching the brain, some the liver, some the retina. **Common AAV serotypes:** - **AAV2/9** — crosses the BBB well, used in CNS gene therapies - **AAVrh10** — good brain penetration, used in Zolgensma - **AAV8** — liver-preferred - **AAV2** — retina-preferred (used in Luxturna) **For MEF2C gene therapy:** The UT Southwestern team will need to choose the right serotype to ensure the therapeutic MEF2C gene reaches the neurons and microglia throughout the brain. This choice significantly impacts the therapy's effectiveness.