A mystery illness stole their kids’ personalities. These moms fought for answers.

https://www.washingtonpost.com/wellness/2024/05/12/down-syndrome-regression-disorder-mothers-support/

But because people with Down syndrome have an extra chromosome 21, they have extra copies of these immune genes — which appear to dysregulate and ramp up the immune system’s response. The result, Espinosa said, is a body that acts like it’s “constantly trying to fight a virus that is not there.”