Clinico-Hematological Profile of Hb Q India: An Uncommon Hemoglobin Variant.

Inherited hemoglobin disorders include thalassemias and structural variants like HbS, HbE, and HbD, Hb Lepore, HbD-Iran, Hb-H disease and HbQ India. HbQ India is an uncommon alpha-chain structural hemoglobin variant seen in North and West India. Patients are mostly asymptomatic and often present in the heterozygous state or co-inherited with beta-thalassaemia. This study was done in a tertiary care teaching hospital in North India over a period of 7 years among patients referred from antenatal and other clinics for screening of hemoglobin disorders. Complete blood count, peripheral blood smear examination and cation exchange high performance liquid chromatography (HPLC) was done to quantify various hemoglobins. HbQ India was diagnosed if the unknown variant hemoglobin was detected within the characteristic retention window. Of a total of 7530 patients screened, 31 (0.4%) were detected to have HbQ India. Of these, 25 (0.3%) patients had HbQ India trait and 6 (0.1%) patients had compound heterozygosity for HbQ India and Beta Thalassemia trait (HbQ India-BTT). All patients were clinically asymptomatic and were detected as part of the screening for hemoglobin disorders. Only two patients with HbQ India-BTT had hemoglobin less than 10 g/dL. In 25 patients with HbQ India trait, HbQ ranged from 13.6 to 24.4% and in 6 patients with HbQ India-BTT, HbQ India ranged from 7.4 to 9.0%. HbQ India is an uncommon structural hemoglobin variant. Although asymptomatic, it may cause diagnostic difficulty in the compound heterozygous state with beta thalassemia. HPLC provides a rapid, accurate and reproducible method for screening of this condition to identify and counsel individuals.