Oligosaccharidosis and Congenital Disorders of Glycosylation: High resolution Oligosaccharide (Free Glycan) Profile, Urine

Condition Description

In glycoprotein storage diseases (GSDs), certain subtypes of congenital disorders of glycosylation (CDGs), and in the mucolipidoses, there is an accumulation of oligosaccharides, free glycans, glycoamino acids, glycolipids and glycopeptides in the urine. Glycoprotein storage diseases are genetic conditions caused by the body's inability to produce specific enzymes. Normally, the body uses enzymes to process, break down and recycle materials in the cells. In individuals with GSD and related diseases, the missing or insufficient enzyme prevents the proper processing and recycling process, resulting in the storage of materials, called oligosaccharides or free glycans and glycoamino acids in virtually every cell of the body. As a result, cells do not perform properly and may cause progressive damage throughout the body, including the heart, bones, joints, respiratory system, immune system and central nervous system. While the disease may or may not be apparent at birth, signs and symptoms develop with age as more cells become damaged by the accumulation of cell materials. The symptoms of these diseases may vary based on syndrome type, and in some cases may resemble a mucopolysaccharidosis disease.

This urinary oligosaccharide and glycan screening is using mass spectrometry, which provides a better sensitivity and specificity than the traditional TLC method. Different from the traditional TLC method, this method successfully detects subtle excretions of abnormal oligosaccharides in mucolipidosis II and III ( I cell disease) as well as other oligosaccharidoses. Conditions screened for are the following:

  • Fucosidosis
  • Alpha-mannosidosis
  • Beta-mannosidosis
  • Sialidosis
  • Aspartylglucosaminuria
  • Schindler disease
  • Kanzaki disease
  • Mucolipidosis II and III ( I cell disease)
  • Galactosialidosis
  • CDGIIb
  • Pompe disease
  • Tay Sachs / Sandhoff (GM2)

Genes (0)

Indications

This test is indicated for:

  • Patients whose clinical evaluations are suggestive of glycoprotein storage or mucopolysaccharidosis diseases.
  • The test detects glycoprotein degradation defects.
  • Multi-system disorders suggestive of congenital disorders of glycosylation, such as CDGIIb.
  • Hydrops fetalis.


Abnormal results should be confirmed by enzyme or molecular analysis.

Methodology

The traditional one-dimensional thin-layer chromatography method for urine oliogsaccharides analysis has limited specificity and sensitivity and provides no structural information that is often needed for diagnoses. This test provides a sensitive screening method for structural analysis of urinary oligosaccharides, glycan and glycoamino acids by liquid chromatography-mass spectrometry using quadrupole - time of flight detection.

Detection and Reference Range

Detection

Interpretation of the urinary oligosaccharide and free glycan profiles are using pattern recognition. Clinical correlations are important. Definite diagnoses should be confirmed by enzyme and molecular analysis.

Reference Range

Interpretation of the urinary oligosaccharide and free glycan profiles are using pattern recognitions.

Specimen Requirements

Listed below are EGL's preferred sample criteria. For any questions, please call 470.378.2200 and ask to speak with a laboratory genetic counselor (eglgc@egl-eurofins.com).
Submit only 1 of the following specimen types
Urine
URN

Requirements
Clean container without additives
5-10 ml.
Freeze sample. Fasting or first void sample is preferable.
Collection and Shipping
Ship frozen sample on dry ice with overnight delivery.

Special Instructions

Include the family history, clinical condition (asymptomatic or acute episode), diet and drug therapy information.

  • Lysosomal Enzyme Screen (LS)
  • Carbohydrate Deficient Transferrin for Congenital Disorders of Glycosylation (BCDGS)
  • N-glycan Structural Analysis for CDGs (BNGLY)
  • Mucopolysaccharide Screen (GA)

How to Order