This data packet contains genotypes, clinical traits, as well as expression traits measured in three regions of the brain: visual cortex, cerebellum, prefrontal cortex. Samples were collected from 803 participants including 388 diagnosed with Alzheimer's disease and 220 diagnosed with Huntington's disease. Genotypes were run using two platforms (Illumina and Perlagen). Expression traits were profiled using a custom Agilent platform. Western-IRB has confirmed that this dataset residing in Sage Bionetworks Repository is 'exempt' under federal regulation 45 CFR 46.101(b)4 and does not involve human subject research as defined by OHRP guidelines.