Test Overview

Test Methodology

Affinity Chromatography / Mass Spectrometry

Test Usage

Screening test for congenital disorders of glycosylation. Note that a positive test could be due to a genetic or non-genetic condition. Reports of abnormal results will include recommendations for additional biochemical and molecular genetic studies to more precisely identify the correct form of CDG.

Reference Range*

Transferrin Mono-oligo/Di-oligo Ratio: <or= 0.06; Transferrin A-oligo/Di-oligo Ratio: <or= 0.011; Transferrin Tri-sialo/Di-oligo Ratio: <or= 0.05; Apo CIII-1/Apo CIII-2 Ratio: <or= 2.91; Apo CIII-0/Apo CIII-2 Ratio: <or= 0.48.

* Reference ranges may change over time. Please refer to the original patient report when evaluating results.

Test Limitations

Other conditions such as hereditary fructose intolerance, galactosemia, and liver disease may result in increased levels of carbohydrate deficient transferrin. Relevant clinical information and the indication for the analysis should be provided with the specimen, in particular for nonpediatric patients.

Test Details

Days Test Performed

Monday, Thursday

Analytic Time

6-11 days

Soft Order Code


MiChart Code

CDT for Congenital Disorders of Glycosylation (Sendout)



CDT Congen Disord Glycosylatio
Mono-oligosaccharide/Di-oligosaccharide transferrin ratio
A-oligosaccharide/Di-oligosaccharide transferrin ratio

+ See More



Laboratory Reference

Mayo CDG (89891)

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Specimen Requirements

Offsite Collection Instructions

Collect specimen in red top or SST tube. Centrifuge, aliquot serum into a plastic vial and freeze.


Yellow Top Tube

Normal Volume

0.2 mL serum

Minimum Volume

0.1 mL serum

Additional Information

Test sent to Mayo Medical Laboratories.

Billing Information

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