[The structure of three major oligosaccharides in the urine of patients with mucolipidosis type II and with two new types of metabolic disease].

The urine of five patients with three distinct diseases ("I Cell disease" and two new types of mucolipidosis) contains sialic acid-rich oligosaccharides in a high amount: 50 to 500 fold the normal. The structure of the major components are as follows alpha-NANA-(2 leads to 6)-beta-Gal-(1 leads to 4)-beta-GlcNAc-(1 leads to 2)-alpha-Man-(1 leads to 3)-beta-Man-(1 leads to 4)-GlcNAc, [alpha-NANA-(2 leads to 6) beta-Gal-(1 leads to 4)-beta-Glc-NAc-(1 leads to 2)-alpha-Man-(1 leads to 3) [beta-Gal-(1 leads to 4)-beta-GlcNAc-(1 leads to 2)-alpha-Man-(1 leads to 6)]-beta-Man-(1 leads to 4)-GlcNAc and alpha-NANA-(2 leads to 6)-beta-Gal-(1 leads to 4)-beta-GlcNAc-(1 leads to 2)-alpha-Man-(1 leads to 3)[alpha-NANA-(2 leads to 6)-beta-Gal-(1 leads to 4)-beta-GlcNAc-(1 leads to 2)-alpha-Man-(1 leads to 6)[-beta-Man-(1 leads to 4)-GlcNAC. These results suggest that a dieficit in alpha-neuraminidase is associated to these three different disorders and that an endo-beta-D-N-acetyglucosaminidase is able to release sialyloligosaccharides by splitting the sialyglycans of glycoproteins.