Missing Hb Q-India Peak in a Triple-Heterozygous Patient with Hb D-Punjab/Hb Q-India/β-Thalassemia Trait

Abstract

Interpretation of variant hemoglobins (Hbs) can pose challenges. We describe a puzzling case with multiple variant Hb peaks that was solved by family studies. A 32-year-old female with anemia and jaundice underwent cation exchange high performance liquid chromatography (HPLC), which revealed near-absence of Hb A along with variant peaks in the D- and C-windows (78.9 and 13.3%, respectively) and normal range of Hb F. As the HPLC did not fit any known pattern, family screening was performed. Her mother was heterozygous for Hb D-Punjab (HBB: c.364G>C) and Hb Q-India (HBA1: c.193G>C) with the hybrid α^Q-India/β^D-Punjab eluting in the C-window on HPLC. Her sister had β-thalassemia (β-thal) trait, while her brother was heterozygous for Hb Q-India. In view of the family study results, the index case was interpreted as a double heterozygote for Hb D-Punjab and β-thal with coinherited Hb Q-India. The Hb Q-India peak [retention time (RT) 4.7 min.] was absent on her HPLC as there were no normal β-globin chains available to bind with the α^Q-India chains. To the best of our knowledge, such an HPLC pattern with a missing Q-India peak, despite having inherited the α^Q-India variant, has not been previously reported. This case illustrates the importance of family screening as an inexpensive and rapid method to resolve difficult and unusual HPLC patterns.

Keywords:

• β-Thalassemia (β-thal)
• Hb D-Punjab
• Hb Q-India
• variant hemoglobin (Hb)

Disclosure statement

The authors report no conflicts of interest. The authors alone are responsible for the content and writing of this article.

Data availability statement

The complete data is available from the corresponding author. The data will be shared on request.