Variant haemoglobin

Keywords: Haemoglobin variants testing

Specimen:

5-20 mL blood in EDTA tube.

Method:

PCR-based analysis.

Application:

The diagnosis of haemoglobin variants, when appropriate after clinical assessment, Full blood count and Haemoglobin electrophoresis.

Prenatal diagnosis.

See also Sickle cell disorders.

Interpretation:

Characterisation of specific haemoglobin variants eg, HbE, HbD, HbLepore. This testing is commonly used in two situations: (1) to explain an underlying haematologic change, which is unlikely to be a thalassaemia based on haematologic analysis; and (2) to confirm a haematologic change suspected of being a variant.

Prenatal diagnosis for at-risk pregnancies, in which DNA testing must be preceded by careful haematologic analysis to give some clue to the DNA laboratory as to which gene (alpha or beta) is likely to be involved.

Reference:

Blain B. Haemoglobinopathy Diagnosis. 2001. Blackwell Science.

Ryan K et al. Significant haemoglobinopathies: guidelines for screening and diagnosis. BJH 2010: 149(1) 35-49

Globin Gene Server (http://globin.cse.psu.edu/globin/)