Silent hemoglobin variant during capillary electrophoresis: A case report

Area of Science:

• Hematology
• Genetics
• Clinical Chemistry

Background:

• Hemoglobin (Hb) variants can interfere with diagnostic tests, impacting patient care.
• Accurate measurement of glycated hemoglobin (HbA1c) is crucial for diabetes management.
• The Hb North Manchester variant (β51(D2) Pro→His; HBB:c.155 C>A) is a rare β-globin gene variant known to affect Hb measurements.

Observation:

• A rare case of Hb North Manchester was incidentally detected in a patient with type 2 diabetes in Northern China.
• The variant was identified using ion-exchange high-performance liquid chromatography (IE-HPLC).
• Standard capillary electrophoresis methods for glycated Hb and Hb analysis failed to detect this specific variant.

Findings:

• Ion-exchange high-performance liquid chromatography successfully identified Hb North Manchester.
• Capillary electrophoresis methods proved insufficient for detecting this rare Hb variant.
• Sanger sequencing confirmed the presence of the Hb North Manchester variant, aiding in its definitive identification.

Implications:

• This case underscores the importance of considering rare Hb variants in diabetes monitoring, especially when standard tests yield unexpected results.
• Clinicians should be aware of potential interferences from Hb variants like Hb North Manchester in glycated Hb measurements.
• Further investigation using methods like Sanger sequencing may be necessary for accurate diagnosis and patient management when variant Hb is suspected.