TCN1 encodes the protein haptocorrin, also known as transcobalamin I, which binds vitamin B12 (cobalamin) in the saliva and protects it from degradation in the acidic environment of the stomach. This initial binding allows B12 to reach the small intestine, where it is then transferred to intrinsic factor for absorption. Variants in the TCN1 gene may affect the stability or availability of B12 in the digestive tract, potentially contributing to suboptimal B12 status. Although not directly involved in cellular B12 transport like TCN2, TCN1 plays a critical early role in vitamin B12 handling.
TCN1 encodes haptocorrin, a protein that binds to and protects vitamin B12 in the stomach, facilitating its delivery to the small intestine for absorption.
Variants in TCN1 may reduce the ability to bind or protect B12 effectively, potentially affecting total B12 levels in the body.
No, TCN1 is involved in the initial transport of B12 through the digestive tract, whereas TCN2 is responsible for delivering B12 into cells.
Indirectly, yes. If B12 is not adequately protected or transported early in the digestive process, it may result in reduced availability and symptoms such as fatigue or neurological problems.