Hemoglobin H disease from Algeria: genetic and molecular characterization.

A case of Hb H disease from Algeria was studied at the genetic and molecular level in order to delineate the pattern of alpha-thalassemia in the Mediterranean population. The family study indicated that both parents had the hematological and clinical manifestation of alpha-thalassemia trait and that the affected sibling had homozygous alpha-thalassemia with 5.6% Hb H, microcytosis and an alpha-/non-alpha-biosynthetic ratio of 0.64. Hybridization in globin cDNA alpha excess suggested that the molecular defect responsible for this form of alpha-thalassemia is a partial deletion of the haploid stock of alpha-globin genes. The Algerian case of Hb H disease studied thus differs from Asian and Negro cases by the mode of inheritance of the alpha-thalassemia mutation involved.