Cytidine monophospho-N-acetylneuraminic acid hydroxylase, pseudogene (CMAHP)

Cytidine monophospho-N-acetylneuraminic acid hydroxylase, pseudogene (CMAHP), is a human unitary pseudogene that is homologous to the functional CMAH gene found in most other mammals[1][4][7]. In non-human mammals, CMAH encodes an enzyme that hydroxylates N-acetylneuraminic acid (Neu5Ac) to form N-glycolylneuraminic acid (Neu5Gc), a major sialic acid component of cell surface glycoconjugates[3][5]. In humans, mutations have rendered the gene inactive—humans do not synthesize Neu5Gc, and the pseudogene produces no active enzyme[1][4][5][7][9]. The lack of Neu5Gc in human tissues is associated with a uniquely human immunological profile and may have played roles in human evolution[5]. The absence of CMAH activity also means that dietary Neu5Gc, notably from red meat and dairy, may be immunogenic and related to chronic inflammation and disease[5]. The CMAHP pseudogene transcript may have additional regulatory roles at the RNA level, including competing endogenous RNA activity influencing cancer outcomes[4]. This locus is not a therapeutic target, as it does not encode a functional protein, but its evolutionary and clinical significance is well established.

Other names

Inactive cytidine monophosphate-N-acetylneuraminic acid hydroxylaseCMAHCMP-NeuAc hydroxylase-like proteinCytidine monophosphate-N-acetylneuraminic acid hydroxylase pseudogeneCMP-N-acetylneuraminic acid hydroxylase