Prealbumin (TTR) is a hormone-binding protein that participates in the plasma transport of both thyroxine and retinol (vitamin A). Prealbumin concentrations are disproportionately high in human ventricular cerebrospinal fluid (CSF). It is reported to be either selectively transported across or synthesized within the blood-CSF barrier. Over 80 different disease-causing mutations in prealbumin have been reported. The vast majority is inherited in an autosomal dominant manner and is related to amyloid deposition, affecting predominantly peripheral nerve and/or the heart. A small portion of prealbumin mutations are apparently non-amyloidogenic. The human amyloid disorders, familial amyloid polyneuropathy, familial amyloid cardiomyopathy and senile systemic amyloidosis, are caused by insoluble prealbumin fibrils.