Coinheritance of Hb D-Punjab and β-Thalassemia: Diagnosis and Implications in Prenatal Diagnosis

Abstract

Hb D-Punjab (HBB: c.364G>C) is an abnormal hemoglobin (Hb) associated with genetic risk in association with Hb S (HBB: c.20A>T). In addition, misdiagnosing homozygosis for hemizygosis may have implication for genetic risk assessment. We present the diagnostic utility of high performance liquid chromatography (HPLC) in differential diagnosis between the Hb D-Punjab homozygote and the Hb D-Punjab/β-thalassemia (β-thal) genotype. The Hb A₂ level measurement may not be a reliable parameter to differentiate between the two conditions. In a screening program for risk prediction, the genotype should be confirmed by family study and/or molecular analysis. Misdiagnosis can have potentially adverse implications in a prenatal diagnosis (PND) program, particularly in areas where consanguinity is common and this Hb D-Punjab variant occurs.

• β-Thalassemia (β-thal)
• Hb D-Punjab
• high performance liquid chromatography (HPLC)
• molecular diagnosis
• prenatal diagnosis (PND)

Declaration of interest

The authors acknowledge the financial and technical support of the Indian Council for Medical Research, New Delhi, India. The authors report no conflicts of interest. The authors alone are responsible for the content and writing of this article.