Characterisation of a molecular switch between amyotrophic lateral sclerosis and frontotemporal dementia

Frontotemporal Dementia (FTD) involves death of neurons in frontotemporal brain-lobes resulting in loss of social-linguistic cognition. The condition is a pre-senile dementia and the second most common after Alzheimer's disease. Mutations in the same gene can cause either FTD or amyotrophic lateral sclerosis (ALS, also known as motorneuron disease). ALS causes loss of neurons connecting brain to muscle leading to paralysis and death. What causes the switch between the two is unknown. FTD and ALS can be caused by rare mutations in the membrane organising protein CHMP2B. The mutations causing ALS cluster in one half of the gene, while mutations causing FTD fall in the other half suggesting that CHMP2B is a critical pivot point between FTD and ALS. We propose to examine the processes stimulated by each mutation to identify signals activated in neurons that would generate either FTD or ALS.