Alpha fetoprotein

Article By:

Baumgarten, Alexander Department of Laboratory Medicine, School of Medicine, Yale University, New Haven, Connecticut.

Last reviewed:April 2021

DOI:https://doi.org/10.1036/1097-8542.025350

A glycoprotein that is normally present in significant amounts only in the serum of the fetus. Alpha fetoprotein (AFP) is an important plasma glycoprotein found in a developing fetus. This protein is also detectable in the mother's blood by passing through the placenta. During fetal development, alpha fetoprotein is produced in the yolk sac, the liver, and other tissues of the gastrointestinal tract. Its role is unknown, but alpha fetoprotein may function as a carrier (or modulator of the concentration) of a small ligand, as an immunosuppressive, as a modulator of intracellular transport of unsaturated fatty acids, as a factor in estrogen transport, or as a means of binding retinoic acid. Abnormal levels of alpha fetoprotein in a pregnant woman can indicate a congenital anomaly (birth defect), tumors (see illustration), or other conditions in the fetus. See also: Congenital anomalies; Developmental biology; Glycoprotein; Liver; Pregnancy; Pregnancy disorders; Prenatal diagnosis; Yolk sac

The content above is only an excerpt.