TTR and prealbumin measurement: The mechanisms of neurogenic OH in hereditary transthyretin amyloidosis are similar to those of peripheral neurodegenerative synucleinopathies, i.e., Parkinson disease, dementia with Lewy bodies and pure autonomic failure, in which dysfunction of the sympathetic nerves is mediated by accumulation of another misfolded protein, α-synuclein, highlighting the high affinity that both misfolded transthyretin and α-synuclein have for the autonomic nervous system [104].