Some problems of hemoglobin patterns in different thalassemic syndromes showing the heterogeneity of beta-thalassemia genes

Globin synthetic ratios in homozygous beta-thalassemia patients from Lebanon

We have studied patients with beta-thalassemia from a Lebanese population having a high rate of consanguineous matings. This population exhibits both elevated and normal levels of Hb A2 associated with high levels of Hb F in homozygotes. The clinical course of the anemia suggests that this population consists of the severe Mediterranean type. Twenty-three unrelated homozygous beta-thalassemia patients investigated for globin synthetic ratios, consisted of 18 beta+ and 5 beta 0 with a non-alpha/alpha range of 0.158-0.465 and 0.25-0.41, respectively. The percentage of G gamma chains in Hb F was determined for 21 of these patients and a mean value of 59% G gamma chain content was found.

A mouse model for beta-thalassemia

A mutation that produces an absolute deficiency of normal beta-major globin polypeptides has been recovered from a DBA/2J male mouse. Most mice homozygous for the deficiency survived to adulthood and reproduced but were smaller at birth than their littermates and demonstrated a hypochromic, microcytic anemia with severe anisocytosis, poikilocytosis, and reticulocytosis and the presence of inclusion bodies in a high proportion of circulating erythrocytes. Mice heterozygous for the deficiency demonstrated a mild reticulocytosis but were not clinically anemic. Analysis of globin chain synthesis in vitro by 3H-leucine incorporation revealed that beta-globin synthesis was nearly normal (95%) in heterozygotes and about 75% of normal in deficiency homozygotes. Molecular characterization of the mutation by restriction analysis revealed a deletion of about 3.3 kb of DNA, including regulatory sequences and all coding blocks for beta-major globin. Based on genetic and hematological criteria, mice homozygous for the mutant allele, designated Hbbth-1, represent the first animal model of beta-thalassemia (Cooley's anemia), a severe genetic disease of humans.

Heterogeneity in beta 0 thalassemia from Algeria: genetic, clinical and molecular studies

Six Algerian patients with beta 0 thalassemia are presented, in addition to the two patients already reported (Godet et al., 1977). Family studies indicate that all the patients had homozygous beta thalassemia characterized by absence of beta globin chain synthesis in peripheral blood. The clinical severity varies from one family to the other and within the same family, from typical Cooley's anemia to thalassemia intermedia and appears to be related to the child death rate observed in each family. The gamma/alpha biosynthetic ratio was 0.36-0.40 in seven patients and 0.2 in the most seriously affected patient. The mRNA beta content in peripheral reticulocytes was less than 1.5% of mRNA alpha in seven patients and 13.3% in one patient. These results indicate that Algerians homozygous for beta 0 thalassemia are heterozygous at the clinical, biochemical and molecular levels.

Clinical and haematological data in 254 cases of beta-thalassaemia trait in Italy

The haematological and clinical data in 254 Italian subjects with beta-thalassaemia trait are reported. 46% of the patients were anaemic, 40% complained of weakness, 19% showed enlargement of the spleen and 10% enlargement of the liver. The haemoglobin levels ranged from 8 to 15.5 g/dl with a normal distribution and a mean of 12.73 for males, 10.93 for females and 11.34 for children (4-15 years). Reticulocyte counts and serum bilirubin levels were slightly increased and both showed a statistically significant relationship with haemoglobin levels. The serum iron level was increased in 27% and decreased in 6% of the cases. Haemoglobin A2 concentrations ranged from 3.5% to 8% with a normal distribution and a mean of 5.37; Hb F values were less than 1% in 36% and varied from 1 to 14% in the remainder. Red cell osmotic fragility was decreased in all but 6% of the subjects: low MCV, MCH and MCHC values were observed in 75%, 86% and 10% respectively. A comparison is made between the data and those obtained by other workers.

An individual with Hb-Lepore-Baltimore- delta beta-thalassaemia in a Yugoslavian family

The clinical, haematological and biochemical findings in a person with delta beta-thalassaemia and Hb-Lepore are described. The patient was a 24-year-old student who suffered from anaemia of intermediate severity with late onset of the clinical manifestations, had minor bone and facial deformities, but had no necessity for regular transfusions. Haemoglobins A and A2 were absent in this individual, and the Hb-Lepore has been identified as Lepore-Baltimore. Heterogeneity of gamma chain of the Hb-F follows the expected pattern. The study provides further evidence that neither beta nor delta chains are synthesized in cis to delta beta-thalassaemia or Hb-Lepore.

Two rare complications of chronic benzene poisoning: myeloid metaplasia and paroxysmal nocturnal hemoglobinuria. Report of two cases

Two patients, one with myeloid metaplasia and the other one with PNH, both due to chronic exposure to benzene are presented. The patient with PNH exhibited also marked monocytosis as a rare hematologic finding of chronic benzene exposure. The etiological relationship between myeloid metaplasia, PNH and chronic benzene exposure is discussed.

Haematological effects of chronic benzene poisoning in 217 workers

Aksoy, M., Dinçol, K., Akgün, T., Erdem, Ş and Dinçol, G. (1971).Brit. J. industr. Med.,28, 296-302. Haematological effects of chronic benzene poisoning in 217 workers. A haematological study consisting of the determination of RBC, WBC, PCV, platelets, and differential counts was carried out, together with bone marrow puncture and haemoglobin analyses in appropriate cases, on a control population of 100 normal people and on 217 male labourers, 95% of whom worked with solvents containing benzene in small shops manufacturing shoes under unhygienic conditions. The concentration of benzene in the workplaces ranged between 30 and 210 p.p.m., and the period of exposure between 3 months and 17 years. In 51 of the 217 workers (23·50%) haematological abnormalities attributable to chronic benzene poisoning were detected. Thus, leucopenia was present in 9·70%, thrombocytopenia in 1·84%, leucopenia associated with thrombocytopenia in 4·6%, pancytopenia in 2·76%, acquired pseudo-Pelger-Huet anomaly in 0·46%, lymphocytosis in 0·46%, giant platelets in 0·46%, eosinophilia in 2·30%, basophilia in 0·46%, and eosinophilia associated with basophilia in 0·46% (the maximum normal levels for eosinophils and basophils were 8% and 2% respectively). Acquired pseudo-Pelger-Huet anomaly was detected in a worker with heterozygous betathalassaemia (HbA₂ 4·1% and HbF 8·7%) in whom the only effect of benzene was on the leucocyte nuclei, all other haematological values being within normal limits. On the other hand, in 33·1% of the workers the haemoglobin was less than 12 g/100 ml and in 32·7% the PCV was less than 40% with the MCV ranging between 86 and 96 μm³. In none of them did MCV exceed 100 μm³. Thirty-one per cent. of these anaemic workers were treated with adequate doses of oral iron, which resulted, in all cases, in a complete disappearance of the anaemia. Therefore, it is difficult to attribute this anaemia to the effect of benzene alone. Thus it is concluded that benzene exerts its harmful effect, primarily on the leucocytes, with eosinophilia and basophilia as inconstant findings, secondarily on the platelets causing thrombocytopenia, and finally on all three series giving rise to pancytopenia.