Mutations in the htt gene lead to the production of an abnormal huntingtin protein with expanded polyglutamine (polyQ) tracts. This mutated protein is prone to aggregation, disrupting normal cellular functions. The most well-known condition associated with htt gene mutations is Huntington's disease (HD). Histologically, HD is characterized by the presence of protein aggregates in neurons, particularly in the striatum and cortex, leading to neuronal degeneration and loss of brain tissue.
