Sialogluciduria in lysosomal diseases: quantitative and qualitative analysis of urinary low molecular sialoglucides from patients with mucopolysaccharidosis and with mucolipidosis

Urinary oligosaccharide excretion in disorders of glycolipid, glycoprotein and glycogen metabolism. A review of screening for differential diagnosis

In recent years great interest has centered around metabolic disorders in which excessive oligosacchariduria is a prominent feature. This review describes the methods of both structural and diagnostic investigations of oligosaccharides in a number of these diseases. Special emphasis has been laid upon simple screening methods which would avail themselves to the clinical chemistry laboratory

Sialidoses, new types of inborn diseases

While mucolipidosis I and its variants are well defined as sialidosis, the basic defect in mucolipidosis II and III is still discussed. The neuraminidase defect in these disorders is generally considered as one of many lysosomal hydrolase deficiencies, accompanied by a high extracellular activity of these enzymes. Our hypothesis of a specific alpha-neuraminidase defect, in these cases, is based on the fact that it is common to numerous tissues and extracellular fluids, in opposite to other hydrolases activities. The choice of the substrate for the alpha-neuraminidase determination appears to be very important, in view of their peculiar specificities.

Increased urinary excretion of free N-acetylneuraminic acid in thirteen patients with Salla disease

Thirteen severely retarded patients with Salla disease, a new type of lysosomal storage disorder, have been studied biochemically. All patients excreted approximately ten times more free sialic acid than normal individuals. The isolated sialic acid was characterized by paper chromatography, thin-layer chromatography, optical rotation, 13C and 1H nuclear magnetic resonance spectroscopy, and mass spectrometry of its permethylated derivative. The results clearly indicated that the excreted sialic acid was identical to N-acetylneuraminic acid. The main sialylated trisaccharide present in the urine of the patients was identified as 3'-sialyllactose by sugar and methylation analysis. The excreted amounts were found to be within normal range.