Lab Test

Carbohydrate Deficient Glycoprotein Syndrome

CDG Studies

Test Codes

MAYO: CDG, EPIC: LAB6791, SOFT: X1CDT

Department

Send Outs

Specimen Collection Criteria

Collect (preferred specimen): One plain Red-top tube.
Also acceptable: One Gold-top SST tube.

Physician Office/Draw Specimen Preparation

Let specimen clot 30-60 minutes then centrifuge to separate serum from cells. Transfer serum to plastic transport tube and freeze (-20°C/-4°F or below).

Preparation for Courier Transport

Transport: 0.1 mL serum, frozen (-20°C/-4°F or below). (Minimum: 0.05 mL)

Rejection Criteria

Gross hemolysis.

Specimens not collected and processed as indicated.

In-Lab Processing

Let specimen clot 30-60 minutes then centrifuge to separate serum from cells. Transfer serum to plastic transport tube and freeze (-20°C/-4°F or below).

Transport: 0.1 mL serum, frozen (-20°C/-4°F or below). (Minimum: 0.05 mL)

Storage

Specimen Stability for Testing:

Room Temperature (20-26°C or 68-78.8°F): 7 days
Refrigerated (2-8°C or 36-46°F): 28 days
Frozen (-20°C/-4°F or below): 45 days

Specimen Storage in Department Prior to Disposal:

Specimen retention time is determined by the policy of the reference laboratory. Contact the Sendout Laboratory with any questions.

Laboratory

Sent to Mayo Medical Laboratories, Rochester, MN.

Performed

Monday, Thursday.
Results available in 6-11 days.

Reference Range

By report.

Test Methodology

Affinity Chromatography/Mass Spectrometry (MS).

Interpretation

Carbohydrate-deficient transferrin is a marker for the autosomal recessive disorder previously known as Carbohydrate Deficient Glycoprotein Syndrome (CDGS). CDGS is caused by various defects involving the glycosylation of glycoproteins. Depending on the site of the biochemical defect and the clinical presentation, five different forms of this syndrome have been described to date. These disorders were recently combined into a larger group of diseases termed "Congenital disorders of glycosylation" (CDG).  Characteristic features of the first patients described included mental retardation, cerebellar hypoplasia, inverted nipples, and unusual subcutaneous fat pads on the buttocks. The phenotype varies and CDGS can be considered a multisystem disorder. The diagnosis should be considered in all patients with mental retardation, cerebellar hypoplasia, liver dysfunction or stroke-like episodes.

The abnormal transferrin isoform pattern in patients with chronic alcoholism is similar to that observed in CDGS. However, unlike most CDGS patients, the relative amount of mono-glycosylated transferrin is much lower.

Clinical Utility

This assay aids in the diagnosis of the various forms of carbohydrate-deficient glycoprotein syndrome (CDGS).

CPT Codes

82373

Contacts

Last Updated

4/10/2021

Microtainer® and Vacutainer® are registered trademarks of Becton, Dickinson and Company.
UroVysion® is a registered trademark of Abbott Laboratories. ThinPrep® is a registered trademark of Hologic, Incorporated.