Huntington disease is an inherited, progressive, incurable neurodegenerative disorder that primarily affects cells in the brain.

The genetic components which trigger Huntington's disease were discovered in the 1990's. Sufferers have a mutation in the Huntingtin gene (HTT). The gene controls the production of the protein Huntingtin, which is known to interact with over 100 other proteins. It is thought to have multiple functions.

However :

Although the genetic basis for this condition has been known for nearly 30 years, how this causes disease is still unresolved. Of late there has been increasing evidence suggesting that dysfunction in macroautophagic/autophagic pathways may contribute to cellular dysfunction and death.

Source : Autophagy Volume 18, Issue 9 (2022)