Molecular and hematological characterization of hemoglobin H disease in the Bengali population of Kolkata, India.

This article reports the incidence of hemoglobin H (HbH) disease among the nontribe Bengali population living in South 24-Parganas of West Bengal. Among 105 patients with unexplained anemia with moderate hematological parameters referred to our laboratory over a period of 2 years, 17 cases (16.19%) were found to have HbH disease identified by hemoglobin electrophoresis. Molecular investigation for two common mutations of α-thalassemia (-3.7α, -4.2α) was carried out in these 17 cases using DNA extraction followed by multiplex polymerase chain reaction. Presence of these common mutations were identified in 10 of the 17 cases. Of them, -3.7α homozygotes (-3.7α/-3.7α), -3.7α/-4.2α double heterozygotes, and -4.2α homozygotes (-4.2α/-4.2α) were found in three, five, and one patient, respectively. The South East Asian (- -SEA) mutation was searched for in one Chinese patient because this mutation is very common among the Chinese population, and he showed the presence of this mutation. Seven patients with HbH disease did not show any of these mutations. These patients may have other α mutations, which need to be studied further. The need to screen for α-thalassemia at the molecular level in patients with unexplained anemia and its implication in the future generation of our society have been discussed in this article.