Haemoglobin Mass Spectrometry for Haemoglobinopathy and Thalassaemia: Peptide mapping

Diagnostic Use

Haemoglobin (Hb) mass spectrometry is useful in the diagnosis of Hb variants and thalassaemia. This testing may be indicated following the results of routine haemoglobinopathy screening, if an unknown Hb variant or thalassaemia is detected. Hb analysis using electrophoretic and chromatographic procedures, such as Hb A1c testing, will often detect Hb variants of uncertain significance. In addition, high oxygen affinity Hb variants are a known cause of polycythaemia and their exclusion forms part of the standard diagnostic work up in cases of unexplained polycythaemia. Liquid chromatography coupled with electrospray ionisation (ESI) mass spectrometry is the method of choice for identifying Hb variants and thalassaemia in these patients.

Department

Genetics - Molecular Pathology

Delphic Registration Code

MOLP

Laboratory Handling

Test Adds

Chilled (2 - 8 degrees Celsius)

Constituent Tests

• Haemoglobin Mass Spectrometry for Haemoglobinopathy and Thalassaemia: Intact protein analysis
• Haemoglobinopathy Screen, Blood
• Thalassaemia Screen, Blood

Synonyms

Hemoglobin
Hemoglobinopathy
Thalassemia

Turnaround Time

4 weeks

Specimen Type

• Whole Blood

Specimen Requirements

Tube/Container Type:

Preferred

• EDTA (Lavender Cap)

Preferred Sample Volume (ml)

4.0

Minimum Sample Volume (ml)

2.0

No of Samples Required

1

Paediatric Specimen Requirements

Tube/Container Type:

Preferred

• EDTA (Lavender Cap)

Preferred Sample Volume (ml)

1.0

Minimum Sample Volume (ml)

0.5

Additional Specimen Information

As genetic testing may be required following mass spectrometry, please do not centrifuge or freeze blood samples.
If storing blood tube prior to delivery, please refrigerate at 4 degrees (transport still at ambient temperature).

Aliquot Instructions

Sample Type

• Whole Blood

Transport to Lab

Ambient (8 - 24 degrees Celsius)

Additional Referral/Aliquot Information

Please provide any relevant patient results, including haemoglobinopathy screening already undertaken with the referral.

Test Method

Prepared haemolysate blood is denatured and digested with trypsin for analysis by direct injection ESI time-of-flight (TOF) mass spectrometry. Multiply charged ion series are matched to corresponding globin peptides produced on digestion with trypsin. Mass changes are used to identify variant peptides.

Contact Canterbury Health Laboratories on +64 3 364 0484 or email LabInfo@cdhb.health.nz

Additional Costing Information

Note: This test is not performed without running intact protein analysis first. The combined cost of this testing is $350.00 (Exclusive of GST).

For the identification of Hb variants by mass spectrometry, both intact protein analysis and peptide mapping is usually required.
Depending on the abnormality detected by mass spectrometry, genetic analysis may also be required.
The combination of tests performed for Hb variant identification will be at the discretion of the laboratory.
The 4 week turnaround time is for a full protein directed investigation, including mass spectrometry and any subsequent genetic analysis required to establish a diagnosis.

Contact Information

Enquiry Form

Contact Information

Enquiry Form