Genetic cause
How do mutations cause FTD and ALS?
We study both rare mutations that run in families and common variants that modify disease risk.
Mutations in progranulin (GRN) are a common cause of inherited FTD, and common variants in TMEM106B strongly influence who develops the disease. How these two genes connect was unknown. We found that they converge on a single molecule: losing GRN lets C-terminal fragments (CTFs) of TMEM106B build up in neuronal lysosomes, and the protective version of TMEM106B keeps CTF levels low (Zeng et al., 2026 (opens in new tab)). CTF levels may be a disease driver we can measure and target.