HTT and early-onset autosomal dominant Alzheimer disease: Indeed, Insoluble aggregation of proteins is a typical pathological feature of neurodegenerative disorders, such as alpha-synuclein (SNCA) aggregates in Parkinson’s disease, TAU aggregates in Alzheimer’s disease, huntingtin (HTT) aggregation in Huntington’s disease, and granular protein aggregation in stress amyotrophic lateral sclerosis and frontotemporal dementia (FTD).