In Rett syndrome, leaky brain blood vessels traced to microRNA
Medical Xpress
February 25, 2026
AI-Generated Deep Dive Summary
MIT researchers have uncovered a significant link between two common genetic mutations causing Rett syndrome and the structural integrity of developing brain blood vessels. Their study reveals that these mutations lead to an overexpression of miRNA-126-3p, a microRNA responsible for disrupting the formation of leaky blood vessels in the brain. By reducing the levels of this microRNA, they were able to restore vascular health and improve outcomes in affected models. This breakthrough highlights the potential of targeting microRNAs as a therapeutic strategy for Rett syndrome.
Rett syndrome is a rare neurological disorder primarily affecting girls, characterized by severe intellectual disabilities and developmental challenges. While the condition was previously linked to mutations in the MECP2 gene, the exact mechanisms underlying its effects on brain function remained unclear. The study pinpoints how these genetic changes disrupt blood vessel development, leading to a compromised vascular system that hinders proper neural connectivity and function.
The researchers utilized advanced molecular techniques to identify miRNA-126-3p as a key player in this process. They found that overexpression of this microRNA interferes with the normal development of endothelial cells lining brain blood vessels, causing them to become permeable and dysfunctional. This leakiness not only impairs oxygen and nutrient delivery to brain tissue but also contributes to the neurological
Verticals
healthmedical
Originally published on Medical Xpress on 2/25/2026