For example, several mutations in the MAPT gene, which encodes the microtubule-associated protein tau (TAU), are associated with Alzheimer’s disease, while mutations in the SPAST gene, which is responsible for coding the microtubule-severing ATPase spastin protein (Spastin) are also involved in neuronal dysfunction [158,159]. The gene discussed is SPAST; the disease is early-onset autosomal dominant Alzheimer disease.