Transthyretin (TTR) , generally called prealbumin, is a plasma protein that plays an important role in physiology such as a transporter of hormone thyroxine and retinal-binding protein. After produced primarily in the liver, TTR is excreted into the plasma. TTR represents a disproportionate fraction (25%) of CSF protein, prompting the suggestion that it is either selectively transported across the blood-CSF barrier or synthesized de novo within the central nervous system. Transthyretin is a constituent found to the neuritic plaques, neurofibrillary tangles, and microangiopathic lesions of senile cerebral amyloid. It has been reported that more than 40 different mutations in the TTR gene associated with amyloid deposition.