HTT and juvenile Huntington disease: This discrepancy has been observed in several NDD-associated proteins, including alpha-synuclein18,19, tau20, amyloid beta21,22 (Aβ), and exon1 of the Huntingtin (Htt) protein14–17 (Httex1), one of the primary components of intracellular protein aggregates found in Huntington’s disease post-mortem brains23–25.