Principle of Method: Qualitative assessment is made of the patterns of bands seen after thin-layer chromatography of an aliquot of urine equivalent to 10 ìg creatinine, using staining with orcinol and resorcinol.
Uses and Limitations of the Method: The method is a useful technique for screening for glycoprotein storage disorders, but any positive results obtained must always be followed up by enzymatic or (in the case of N-acetylneuraminic acid storage disease) quantitative metabolite confirmation. Abnormal patterns of bands are obtained for the following conditions: a-mannosidosis, fucosidosis, GM1-gangliosidosis (all types), Morquio disease type B, sialidosis, galactosialidosis, aspartylglycosaminuria, N-acetyl neuraminic acid storage disease (infantile and later-onset forms) and I-cell disease. The test is especially useful for screening for the sialidoses, aspartylglycosaminuria and NANA storage diseases because these conditions are not readily diagnosed by white cell enzyme assay. The results obtained for fucosidosis are rather subtle and this disease may be missed by the method. Neonates often give strong non-specific patterns of bands which can be difficult to interpret. It is stressed that the method is a useful supplement to white cell lysosomal enzyme screening and not an alternative procedure.
Specimen Requirements: Urine. 10-20 ml in a sterile container without preservative. Freeze if not sending immediately but can be transported to the laboratory at room temperature.
THE LABORATORY RECOMMENDS USE OF A COURIER SERVICE OR ROYAL MAIL SPECIAL DELIVERY FOR SENDING ALL SPECIMENS TO THE LABORATORY.