Jaonna Jen and colleagues identify mutations in EXOSC3, encoding a core RNA exosome component, causing pontocerebellar hypoplasia type 1 (PCH1), a recessive disorder with heterogeneous defects in brain development. Nine out of 13 individuals diagnosed with PCH1 had missense, frameshift or exon-skipping mutations in EXOSC3, suggesting a critical role of RNA metabolism in normal brain development.
- Jijun Wan
- Michael Yourshaw
- Joanna C Jen