[Hb Q-H: study of in vitro globin chain synthesis in reticulocytes and erythroblasts].

: The case is reported of a 24-year-old Chinese patient with congenital hemolytic anemia (Hb 95 g/l, MCV 71 fl, MCHC 29 g%, reticulocytes 165% RBC). Clinical examination revealed jaundice and marked splenomegaly. Isoelectric focusing of Hb and Hb chains showed the absence of HbA, the presence of rapid Bart's and H Hb and the presence of an alpha chain variant alpha Q-Thailand, alpha 74 Asp----His (confirmation by fingerprinting of Hb). In vitro globin chain synthesis in reticulocytes and erythroblasts indicates that this variant is localized in an alpha-thal-2 chromosome. Furthermore, this variant does not exhibit any transcriptional defect of the alpha Q gene or any instability, since its association with a second alpha-thal-1 chromosome leads to a deficit of alpha chain production identical to that observed in Hb H disease (alpha alpha 0/alpha 0 alpha 0).