[Discovery of hemoglobin J Baltimore in an episode of methemoglobinemia in an infant]. / Découverte d'une hémoglobine J Baltimore au cours d'un épisode de méthémoglobinémie chez un nourrisson.

A case of a heterozygote for Hb J Baltimore is reported in a French family. This variant hemoglobin was coincidentally discovered during an episode of methemoglobinemia in a 6-week-old baby. The father and one of the brothers were also carriers of the trait. Hematological findings for all of them were normal. As Hb J Baltimore is a frequently occurring hemoglobin variant, we discuss: its possible role in the appearance of methemoglobin, and whether this mutation in different racial groups (Caucasians of West Europe, Canadians, and American blacks) has a common origin or more probably arises from a number of independent mutations.

[Hemoglobin E: report of the first 2 cases in French subjects]. / Hémoglobinose E: présentation des deux premières observations chez des sujets d'origine française.

Hemoglobin E has been discovered casually in the blood of two French donors: one coming from the Alsace region, the other one coming from the Champagne region. In the two cases, the hemoglobin E is in an heterozygote state and takes the place of 33 per cent of the total haemoglobin in the first and 24 per cent in the second. We investigated in their families and found that other members of these families had hemoglobin E. Each time, it was associated with a microcytosis and polycythaemia without anemy or iron deficiency. The red cells morphology shows many microspherocytes and target-cells. There is no relationship between these two families and the research of an asiatic antecedent proved negative. These two observations give a supplementary proof that the geographic repartition of the hemoglobin E is larger than what we read in the first publications and shows the interest to study the hemoglobin of unexplained polycythaemia with microcytes in the blood of blood donors.

[Deformability of thawed erythrocytes: introduction of a new preservative solution]. / Déformabilité des érythrocytes décongelés. Apport d'une nouvelle solution protectrice.

Recently, KANE et al. (Centre de Transfusion Sanguine, Strasbourg) designed an original preservative medium, called ESOC, allowing a prolonged storage of thawed RBC. We studied on 15 days the evolution of thawed RBC deformability, while RBC where kept preserved, on the one hand in this ESOC solution, on the other hand in physiologic water, without any preservative medium. We tried to correlate this rheological evolution with cellular ATP, cellular 2,3-DPG and membrane proteins evolution. Deformability was measured by filterability with an Hemorheometre. The results are given as a rigidity index, IR. In ESOC, IR and cellular ATP stay in normal values during the 15 days. In physiologic water, deformability decreases strongly and IR is out of normal values after the fifth day. Cellular ATP decreases out of normal values as soon as the third day. 2,3-DPG decreases in both media. Membrane proteins electrophoresis does not show any difference neither in ESOC nor in physiological water, all fifteen days long. We only observed parallelism between deformability and cellular ATP and IR was higher than normal values. We found no correlation between deformability and 2,3-DPG. We also can conclude, with this study, that ESOC allows a good preservation of thawed RBC and by this way complies with the needs for delayed transfusion in current practice.

Detection of haemoglobinopathies at birth in Togo.

The incidence and nature of haemoglobinopathies were investigated at birth in Togo, using isoelectric focussing on 385 samples of umbilical cord blood. Abnormalities were found in 37.6% of blood samples: Hb A/S, 18.7% (0.5% with Hb Bart's); Hb A/C, 8.9% (0.3% with Hb Bart's); Hb S/C, 1.3% (0.3% with Hb Bart's); Hb S/S, 1%; Hb C/C, 0.3%; isolated Hb Bart's, 5.7%; gamma chain variants 0.8%; acetyl Hb F greater than Hb A, 1%. To date now, no systematic screening of Hb abnormalities has been performed in Togo. Our results showed that Hb S is the principal abnormal Hb found in the population which we studied, with a sickle cell gene frequency of qs = 0.110 and an Hb C gene frequency of qc = 0.053. Our work also confirmed the presence of alpha and beta + thalassaemias (acetyl Hb F greater than Hb A) in Togo. One of the advantages of investigating umbilical cord blood by isoelectric focusing is that detection of Hb S/S and Hb S/C (which had an incidence of 2.3% in our study) can be carried out at birth, allowing the children to be taken care of as soon as possible. About 150,000 children are born each year in Togo, and the infant mortality is estimated at 5 per 100 live births in Lomé and at 10 per 100 live births outside the capital.

Germline mosaicism for an alanine to valine substitution at residue beta 140 in hemoglobin Puttelange, a new variant with high oxygen affinity.

Hb Puttelange [beta 140(H18)Ala-->Val] was found as a de novo mutation in two siblings of a French family suffering from polycythemia. Both parents were phenotypically normal and exclusion of paternity has been ruled out by the study of several polymorphic markers located on different chromosomes. The structural modification of Hb Puttelange was established by reversed-phase HPLC analysis of the tryptic digest of the abnormal chain. The amino acid composition of an abnormal beta T14 peptide revealed that one of the four residues of Ala was replaced by a Val. Tandem mass spectrometry demonstrated that the substitution concerned position beta 140 (H18). This hemoglobin displays an increased oxygen affinity that is responsible for the polycythemia. De novo mutations, as demonstrated again in the case of this variant, have the highest probabilities of detection when they lead to pathological manifestations. They may result either from a somatic mutation in a very early stage of the embryological development of the propositus or may have a parental origin with occurrence of a germline mosaicism. The study of the beta-globin gene indicated that this case of Hb Puttelange probably arose from a mutation affecting a part of the germline of the father, therefore leading to a true recurrence risk.