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Transthyretin

Meaning

Transthyretin (TTR), formerly known as prealbumin, is a homotetrameric transport protein synthesized primarily by the liver, choroid plexus, and retina. Its critical physiological role is the serum transport of the thyroid hormone thyroxine (T4) and, in complex with retinol-binding protein (RBP), the transport of Vitamin A (retinol). Clinically, its concentration serves as a sensitive, albeit non-specific, marker of nutritional status and hepatic synthetic function due to its short half-life.