Hemolytic anemia secondary to a familial (hereditary) defect in hemoglobin synthesis; report of a case with radioiron studies

Hereditary sideroblastic anemia and glucose-6-phosphate dehydrogenase deficiency in a Negro family

Detailed clinical and genetic studies have been performed in a Negro family, which segregated for sex-linked sideroblastic anemia and glucose-6-phosphate dehydrogenase (G-6-DP) deficiency. This is the first such pedigree reported. Males affected with sideroblastic anemia had growth retardation, hypochromic microcytic anemia, elevated serum iron, decreased unsaturated iron-binding capacity, increased (59)Fe clearance, low (59)Fe incorporation into erythrocytes, normal erythrocyte survival ((51)Cr), normal hemoglobin electrophoretic pattern, erythroblastic hyperplasia of marrow with increased iron, and marked increase in marrow sideroblasts, particularly ringed sideroblasts. Perinuclear deposition of ferric aggregates was demonstrated to be intramitochondrial by electron microscopy. Female carriers of the sideroblastic gene were normal but exhibited a dimorphic population of erythrocytes including normocytic and microcytic cells. The bone marrow studies in the female (mother) showed ringed marrow sideroblasts. Studies of G-6-PD involved the methemoglobin elution test for G-6-PD activity of individual erythrocytes, quantitative G-6-PD assay, and electrophoresis. In the pedigree, linkage information was obtained from a doubly heterozygous woman, four of her sons, and five of her daughters. Three sons were doubly affected, and one was normal. One daughter appeared to be a recombinant. The genes appeared to be linked in the coupling phase in the mother. The maximum likelihood estimate of the recombination value was 0.14. By means of Price-Jones curves, the microcytic red cells in peripheral blood were quantitated in female carriers. The sideroblast count in the bone marrow in the mother corresponded closely to the percentage of microcytic cells in peripheral blood. This is the second example in which the cellular expression of a sex-linked trait has been documented in the human red cells, the first one being G-6-PD deficiency. The coexistence of the two genes in doubly heterozygous females has made it possible to study correlations in cell counts; our studies showed a strong positive correlation except in the probable recombinant in which a reciprocal relation held which indicated that X-inactivation was at least regional, rather than locus by locus.

The kinetics of iron metabolism in normal growing swine

Plasma and red cell iron turnover rates were determined in 18 normal growing swine by the use of tracer doses of Fe(59). Body surface counting was performed on a representative group of animals following the injection of the isotope. The mean half-time of plasma iron disappearance was 1.19 +/- 0.26 hours. Two exponential rates of disappearance of Fe(59) from the plasma were observed in 15 of the pigs and a single rate was observed in the other 3. The mean plasma iron turnover rate was 1.11 +/- 0.34 mg./kg. day. The average maximum incorporation of Fe(59) into the erythrocytes was 92 +/- 9 per cent. The mean red cell iron incorporation rate was 1.10 mg./kg. day, but an average of 0.42 mg./kg. day of this was calculated as being due to increasing red cell mass incidental to body growth, so that the true mean red cell iron turnover rate was 0.59 +/- 0.19 mg./kg. day. The average "apparent" red cell life span was 63 +/- 16 days. This is in agreement with the red cell life span of 62 days determined previously with glycine-2-C(14).

The incidence and significance of iron-containing granules in human erythrocytes and their precursors

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[Constitutional pathology of erythropoiesis]

The concept and definition of constitutional pathology. Genetic erythropathies such as constitutional spherocytosis, leptocytosis, ovalocytosis and drepanocytosis and their relation to hemolytic clinical syndromes are discussed. Sickle cell trait, sickle cell anemia, and sickle cell disease have to be distinguished as clinical manifestations of drepanocytosis. They represent a special variety of a « status degenerativus » (Bauer). Four genetic types of human hemoglobin have so far been identified that differ from each other by their molecular architecture and chemical reactivity. Several constitutional abnormalities of erythropoiesis other than those just mentioned are discussed: a hereditary defect in hemoglobin synthesis; erythroid multinuclearity; acanthocytosis; Fanconi's syndrome of hypoplasia and abiotrophy of the bone marrow as another variety of a status degenerativus.