 HS-O-sulfotransferase (Hs2st) occupies a critical position in the succession of enzymes responsible for the biosynthesis of HS, catalysing the transfer of sulfate to the C2-position of selected hexuronic acid residues within the nascent HS chain.Mice that lack HS2ST undergo developmental failure after midgestation, the most dramatic effect being the complete failure of kidney development.This family is related to .