A rare hemoglobin variant (Hb Iraq-Halabja) causing spuriously low hemoglobin A1c values

Area of Science:

• Clinical Chemistry
• Hematology
• Genetics

Background:

• Hemoglobin A1c (HbA1c) is a critical biomarker for long-term glycemic control in diabetes management.
• Accurate HbA1c measurement is essential for effective diabetes treatment and preventing complications.
• Various factors, including hemoglobin variants, can interfere with standard HbA1c assays.

Observation:

• A diabetic patient presented with unexpectedly low HbA1c levels when measured using ion-exchange high-performance liquid chromatography (HPLC).
• Standard laboratory and patient-related factors did not explain the discrepant HbA1c results.
• Genetic investigation revealed the patient was heterozygous for a rare hemoglobin variant, Hb Iraq-Halabja (β10 Ala→Val).

Findings:

• The rare Hb Iraq-Halabja variant was identified as the cause of spuriously low HbA1c readings.
• This represents the second documented case of the Hb Iraq-Halabja variant in scientific literature.
• The presence of this variant interferes with the accurate quantification of HbA1c via HPLC.

Implications:

• Clinicians must recognize the limitations of HbA1c assays and be aware of potential interferences from hemoglobin variants.
• Discrepant or unusual HbA1c results warrant further investigation to identify underlying causes, such as rare hemoglobinopathies.
• Accurate HbA1c measurement is crucial for appropriate diabetes management and patient care.