title: N-glycolylneuraminic acid deficiency in humans.
abstract: Classic studies suggested that the common mammalian sialic acid N-glycolylneuraminic acid (Neu5Gc) is an oncofetal antigen in humans, being immunogenic in adult humans and yet apparently expressed in human fetuses and tumors. We and others have recently found that the human deficiency of Neu5Gc can be explained by an inactivating mutation in the gene encoding CMP-N-acetylneuraminic acid hydroxylase. Thus, Neu5Gc is not an oncofetal antigen in the classical sense, and other explanations must be found for the observed expression pattern. This review provides an update on this matter, and considers a variety of other old and new questions that arise from it.
authors.affiliation: Glycobiology Research and Training Center and Department of Medicine, University of California, San Diego, La Jolla, CA 92093-0687, USA. avarki@ucsd.edu
authors.forename: A
authors.initials: A
authors.lastname: Varki
mesh_terms: D000818:Animals; D005333:Fetus; D017353:Gene Deletion; D006801:Humans; D006899:Mixed Function Oxygenases / Q000172:deficiency* / Q000235:genetics* / Q000378:metabolism; D009369:Neoplasms / Q000378:metabolism; D009438:Neuraminic Acids / Q000378:metabolism*; D012794:Sialic Acids / Q000378:metabolism
chemical_list: D009438:Neuraminic Acids; D012794:Sialic Acids; C032592:N-glycolylneuraminic acid; D006899:Mixed Function Oxygenases; C074383:CMPacetylneuraminate monooxygenase