TARDBP and juvenile Huntington disease: Neurodegenerative conditions such as Alzheimer’s disease (AD), Huntington disease (HD), as well as Parkinson disease (PD) and dementia with Lewy bodies (DLB) are proposed to be “secondary” TDP-43 proteinopathies in which TDP-43 pathology occurs in the context of the distinctive hallmark pathology of each of these disorders [1, 21, 37, 47, 51].