[Hemoglobin H disease. Presentation of a case]. / La malattia da emoglobina H. Presentazione di un caso.

Haemoglobin H (Hb H) disease, the most important clinical form of alpha-thalassaemia, shows remarkable clinical variability. Hb H si an unstable tetramer of beta-globin chains which accumulates because of the lack of adequate numbers of alpha-globin chains and precipitates in the red cells, causing their premature destruction. A case of Hb H disease in a 9-yr-old child, admitted into hospital for acute haemolysis after use of pyrazolone derived, is presented. Haematologic data with synthesis in vitro of globin chains were obtained from the parents and sister. The clinical and haematologic features of this form of haemoglobinopathy are briefly discussed in the light of recent knowledges of his genetic mechanism of transmission.