TTPA

The TTPA gene encodes alpha-tocopherol transfer protein (α-TTP), a liver-enriched cytosolic protein. It selectively binds alpha-tocopherol (the active form of vitamin E) and mediates its transfer to very low-density lipoproteins (VLDL) for systemic delivery, maintaining vitamin E homeostasis. Common aliases include TTP and α-TTP.
Mutations in TTPA cause autosomal recessive ataxia with vitamin E deficiency (AVED), leading to progressive cerebellar ataxia and peripheral neuropathy. Current treatment uses high-dose vitamin E supplementation. Gene replacement or protein replacement therapies are in preclinical research, but no targeted drugs have been approved for AVED yet.