Hemoglobin A2 Levels Research Articles

The blood groups and haemoglobins of the Kunama and Baria of Eritrea, Ethiopia

SummaryThe Kunama and Baria tribes inhabit north-west Eritrea, Ethiopia, and are both of somewhat negroid appearance. Blood samples were tested for blood groups of seven systems, for glucose-6-phosphate dehydrogenase deficiency and for abnormal haemoglobins. Their blood groups show them to be of mixed Caucasoid-Negroid origin with rather more negroid marker genes than most of the surrounding populations. Abnormal haemoglobins were absent but males of both tribes included about 4 per cent of cases of glucose-6-phosphate dehydrogenase deficiency, and there were some cases of raised levels of haemoglobin A2 (possibly due to thalassaemia) and of foetal haemoglobin in adults. Thalassaemia and glucose-6-phosphate dehydrogenase deficiency are likely to have been favoured by natural selection in an environment which was formerly malarious, with a high proportion of Plasmodium falciparum infection.

Haematological data in 312 cases of -thalassaemia trait in Thailand.

Summary. The haematological data are presented in 312 individuals of Thai or Chinese extraction with the high A2β‐thalassaemia trait. The mean haemoglobin concentrations were 12.1 g% among males and 10.8 g% among eemalcs; 54% of the subjects were not anaemic and all were asymptomatic. Low MCV, MCH and MCHC values were found in 67%, 81% and 6% respectively; erythrocytosis was detected in 34%. Variable hypochromia and microcytosis were usually present, but leptocytosis and red cell basophilic stippling were often absent. Decreased red cell osmotic fragility was always detected. Fifteen cases were found to have normal red cell morphology and 17 normal red cell osmotic fragility. The reticulocyte counts, although ranged up to 12%, were normal in the majority. The serum iron levels and unsaturated iron binding capacity were normal except in 11% of the cases where the scrum iron levels were lower than 50 μg%. Haemoglobin A2 levels varied from 3.4 to 7.8% with a normal distribution and a mean of 5.2%. Haemoglobin F levels varied from o to 7.8% with 58% elevated values. Analysis of variance revealed intrafamilial segregation of both haemoglobin A2 and haemoglobin F levels. The literature is reviewed and findings are compared.

Juvenile myeloid leukemia with fetal erythropoiesis.

A case of juvenile myeloid leukemia in a 21/2-year-old girl is described. Apart from the typical clinical features encountered, this case was characterized by a fetal pattern of erythropoiesis, with exceptionally high levels of fetal hemoglobin, up to 85%, associated with decreased levels of hemoglobin A2 and carbonic anhydrase. There was also a slight elevation of the sodium content and sodium outflux in the patient's red blood cells similar to that recorded in six newborn babies. Significance of these findings is discussed in relation to current concepts of type of erythropoiesis found in this form of leukemia.

Similarities of the Erythrocytes in Juvenile Chronic Myelogenous Leukemia to Fetal Erythrocytes

Abstract A 4-yr-old boy was studied who showed typical findings of juvenile chronic myelogenous leukemia, including massive hepatosplenomegaly, thrombocytopenia, low leukocyte alkaline phosphatase, and absence of a Philadelphia chromosome. The erythrocytes of the patient exhibited many characteristic features of erythrocytes of newborn infants: the fetal hemoglobin concentration was greatly elevated (72%); the oxygen dissociation curve of the whole blood was displaced to the left of the curve from normal adult blood; the hemoglobin A2 level and the erythrocyte I antigen titer were reduced; and a structural analysis of the γ-chain of the fetal hemoglobin showed the glycine to alanine ratio in γ-136 to be typical of the neonatal pattern. These findings support the suggestion that juvenile chronic myelogenous leukemia is accompanied by reversion to a fetal pattern of erythropoiesis.

Haemoglobin A2 level in pregnancy.

The haemoglobin A(2) level was measured in 217 pregnant and 137 non-pregnant patients. Twenty-eight patients were reinvestigated at least six weeks after delivery. There was no significant difference in the mean haemoglobin A(2) level in pregnancy (2.4 +/- 0.8%) and the mean haemoglobin A(2) level in the non-pregnant controls (2.3 +/- 0.6%). In all anaemic patients whose A(2) level was raised in pregnancy the level remained elevated after delivery.

Hereditary persistence of foetal haemoglobin in a Thai family: the first instance in the mongol race and in association with haemoglobin E.

Summary. Hereditary persistence of foetal haemoglobin is described in a Thai family. The AF heterozygotes were healthy and had normal haematological findings except the decrease in haemoglobin A2 level and the presence of a large amount of haemoglobin F. The latter, comprising 21–22 per cent, is higher than in the Greek but lower than in the Negro counterparts. Three persons, who were heterozygous for both haemoglobin E and high F genes, were not anaemic but had numerous target‐erythrocytes; haemoglobin E constituted 40 per cent, the rest being haemoglobin F. Acid‐elution staining revealed haemoglobin F in every red cell in both AF and EF heterozygotes. The absence of haemoglobin A in the latter suggests allelism between this type of hereditary persistence of foetal haemoglobin and haemoglobin E or β‐structural gene.

THE INCIDENCE OF ELEVATED HEMOGLOBIN A2 LEVELS IN THE AMERICAN NEGRO.

Article1 January 1964The Incidence of Elevated Hemoglobin A2 Levels in the American NegroMICHAEL A. GOLDSTEIN, M.D., NONGNUCH PATPONGPANIJ, M.D., VIRGINIA MINNICH, M.S.MICHAEL A. GOLDSTEIN, M.D.Search for more papers by this author, NONGNUCH PATPONGPANIJ, M.D.Search for more papers by this author, VIRGINIA MINNICH, M.S.Search for more papers by this authorAuthor, Article, and Disclosure Informationhttps://doi.org/10.7326/0003-4819-60-1-95 SectionsAboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissions ShareFacebookTwitterLinkedInRedditEmail ExcerptHemoglobin A2is present in a concentration of less than 3.3 per cent of the total hemoglobin in all normal adults (1). Elevation above this level is known to accompany the erythrocyte abnormalities seen in classical thalassemia trait (1, 2). Whereas thalassemia major has rarely been described in the American Negro, many cases of sickle cell thalassemia have been reported in this race (summarized by Dacie (3)). It seemed of interest, therefore, to screen a random population of Negroes for an exact estimate of the prevalence of elevated hemoglobin A2values. The results obtained revealed an increased amount of hemoglobin...

The Incidence of β‐Thalassaemia in Greek and Italian Migrants in Australia and its Effects in Pregnancy

Considerable interest and attention has been manifested during the last decade in the distribution and incidence of the various types of abnormal haemoglobins and a large body of evidence relating to the haemoglobins S, C, D and E has been accumulated. The difficulty in establishing a definite diagnosis of the thalassaemia trait has, however, largely excluded this condition from the statistical studies.In our investigation into the incidence of thalassaemia in the Greek and Italian population of South Australia we have used two approaches to the problem. Firstly, we estimated the haemoglobin A2 levels in the pregnant population at a maternity hospital on the assumption from previous work of our own and other workers (Josephson, Masri, Singer, Dworkin and Singer, 1958) that raised haemoglobin A2 levels are found only in thalassaemia of the β type, in some patients with megaloblastic anaemia and in congenital spherocytic anaemia. These two latter conditions are relatively easy to differentiate on routine haematological grounds. Secondly, the bloods of all pregnant women with haemoglobin values of less than 11.O g. per 100 ml. were surveyed in an attempt to find any cases of thalassaemia with normal haemoglobin A2 values on the grounds of microcytic anaemias with normal serumiron levels and showing no response to iron therapy.Apart from selected case reports there are few factual data available in the literature on the overall effects of pregnancy on the haematological status of the patient with thalassaemia. This aspect has been investigated in conjunction with the studies of the incidence of the β type of thalassaemia trait.