The function of NANS (N-acetylneuraminate synthase, Ensembl gene identifier ENSG00000095380) is as follows. Catalyzes the condensation of phosphoenolpyruvate (PEP) and N-acetylmannosamine 6-phosphate (ManNAc-6-P) to synthesize N- acetylneuraminate-9-phosphate (Neu5Ac-9-P) (PubMed:10749855). Also catalyzes the condensation of PEP and D-mannose 6-phosphate (Man-6-P) to produce 3-deoxy-D-glycero-beta-D-galacto-non-2-ulopyranosonate 9- phosphate (KDN-9-P) (PubMed:10749855). Neu5Ac-9-P and KDN-9-P are the phosphorylated forms of sialic acids N-acetylneuraminic acid (Neu5Ac) and deaminoneuraminic acid (KDN), respectively (PubMed:10749855). Required for brain and skeletal development (PubMed:27213289). .