This should be the first diagnostic test performed for MPS disorders. Urine should be sent prior to or with samples for enzyme analysis. Enzyme analysis will normally only be performed when an abnormal mucopolysaccharide pattern has been identified in urine or there is family history of a specific disorder. Routinely all urine samples are also tested for oligosaccharide and sialic acid containing conjugates by thin layer chromatography (TLC).
Analysis of urinary oligosaccharides by TLC stained with orcinol and resorcinol for oligosaccharides and sialic acid containing conjugates. This test is not always easy to interpret but complements the lysosomal enzyme and urinary MPS screens and can be useful in detection of some oligosaccharide/glycoprotein disorders.
|Test||Required specimen & volume||Special precautions||Turnaround time||Reference ranges||Section|
2-D electrophoresis of GAGs*
|10ml fresh plain U, 10ml AF||To reach the laboratory within 72 hours of sampling||3 working weeks||Qualitative||Lysosomal|
|Oligosaccharide screen||3ml plain U. Age of patient must be specified||To reach the laboratory within 72 hours of sampling||3 working weeks||Qualitative||Lysosomal|
Quantitative sialic acid
Sialic acid storage disease, Sialidosis, Galactosialidosis
|2 – 3ml plain U, CC. Age of patient must be specified||To reach the laboratory within 72 hours of sampling||4 working weeks||Age-matched controls quoted||Lysosomal|
* All samples must be accompanied by relevant clinical details. This is particularly imperative for urine amino acids, urine organic acids, urine mucopolysaccharides and all samples for prenatal diagnosis. Reports may be withheld where samples are received without clinical details as an accurate interpretation may not be possible without them.