Hb AS Research Articles

Genetic studies on the Kolams of Andhra Pradesh, India.

A total of 220 persons belonging to the Kolam tribe in the Adilabad District of northwest Andhra Pradesh have been tested for 18 red cell eyzyme systems and for haemoglobin. Generally, the gene frequencies for the systems which showed electrophoretic variation were within the range for Indian populations; the gene frequency for AK1 is high by Indian standards and Hb AS is present. LDH Calcutta 1 was not detected in this population and a single example of PHI 2-1 was observed.

Growth and development in children with sickle-cell trait. A prospective study of matched pairs.

To ascertain if sickle-cell trait (Hb AS) impairs physical growth and cognitive development, we prospectively investigated 50 matched pairs of black children. For each child with Hb AS, an Hb AA child was matched at birth for sex, birth date, birth weight, gestational age, five-minute Apgar score and socioeconomic status. Between the ages of three and five years, the members of each matched pair were evaluated, with one month of one another, by persons "blind" to the hemoglobin genotype. Twelve outcome measurements were obtained at evaluation: height, weight, head circumference, skin-fold thickness, cross-sectional area of arm muscle, bone age, five scores of the McCarthy Scales of Children's Abilities, and the Peabody Picture Vocabulary Test. There were no statistically significant differences in these measurements favoring the AA group. The results show that children with sickle-cell trait in this age group have no deficits in standard measurements of growth and development and emphasize the importance of rigorous methods when clinical groups are assembled and compared.

Genetic studies on the Savara and Jatapu Tribes of Andhra Pradesh, India.

A total of nearly 300 persons belonging to the Savara and Jatapu tribes in the Srikakulum District of northern Andhra Pradesh have been tested for electrophoretic variation in 13 red cell enzyme systems, and also haemoglobin. The gene frequencies for the systems showing variation are within the range for other South Indian populations, and there are no significant differences between the two tribal groups investigated in this report except in the case of adenylate kinase. The Jatapu (along with the Kadar of Kerala) have the highest frequency of AK1 so far reported in India. Both the Savara and Jatapu showed a low frequency for Hb AS, and LDH-Calcutta 1 was not detected in either population.

Folic acid deficiency in sickle cell anaemia.

Megaloblastic anaemia responding to folic acid has been reported in a number fo patients with sickle cell anaemia. The incidence of reduced serum and erythrocyte folate levels in such patients remains unclear, however. Serum and erythrocyte folate contents were measured microbiologically in patients with sickle cell anaemia as well as in two control groups with sickle cell trait or normal haemoglobin pattern. Low serum and erythrocyte folate values were significantly more common in 61 sickle-cell patients than in each of the two socio-economically-matched control groups including 61 subjects with Hb AS and 69 blacks with Hb AA. There was no correlation between serum folate and haematocrit or reticulocyte count. The erythrocyte folate, measured before and after removal of reticulocytes, remains a reliable indicator of deficiency of folic acid in sickle-cell patients despite variable degrees of reticulocytes. Folate therapy resulted in higher haematocrits in three of four sickle-cell patients with low serum and low erythrocyte folate values, but in only one of 12 patients with low serum folate and normal erythrocyte folate. These findings are consistent with other observations that folate requirement may be increased in chronic haemolytic disorders and suggest that erythrocyte folate values should be obtained in sickle-cell patients suspected of having folate deficiency.

Energy Expenditure In Sicklemia

To the Editor.— The article by J. R. Murphy (225:981, 1973) concerned the prevalence of sickle cell hemoglobin (Hb AS) in football players and offered the hypothesis that men with sickle cell trait would not have limited physical capabilities. During a mission performed in Dahomey by the Institute of Anthropology of Rome University, the energy expenditure of two groups of 15 adults in apparent good health was examined, one group with normal adult hemoglobin (Hb A) and the other with Hb AS. The two groups were selected to show similar somatometric values, also similar to the average values of the examined population as a whole. The energy expenditure was measured at rest and at the cycloergometer, with power levels of 483 and 790 kg/meter, respectively. Respiratory gas analysis was carried out by means of an open-circuit Hartmann and Braun apparatus. Data of the Table show that the energy expenditure under

Genetic markers and anthropometry in the populations of the Egyptian oases of El-Kharga and El-Dakhla.

The populations of two Western Desert Egyptian oases have been studied for various genetic markers of the blood and some anthropological characters. Hb AS was found in 9%. Blood group frequencies were

Sickle Cell Hemoglobin (Hb AS) in Black Football Players

The prevalence of Hb AS, the sickle cell trait condition, was determined in black football players in the National Football League. Hemoglobin electrophoresis on cellulose acetate of 579 blood samples revealed 39 (6.7%) with Hb AS, 11 (1.9%) with Hb AC, 6 (1.0%) with elevated A2, and 2 samples with a combination of Hb A and a rapidly migrating hemoglobin. This prevalence of Hb AS, 6.7%, is not significantly different from that found in the black population in the United States, indicating that there has not been a selective exclusion from professional football of individuals with Hb AS due to possible limitations in physical capabilities.

Sickle cell hemoglobin (Hb AS) in black football players

Sickle cell hemoglobin (Hb AS) in black football players

Incomplete renal tubular acidosis in sickle cell disease

To evaluate renal acidification capacity in sickle cell nephropathy 6 subjects with sickle cell trait (Hb AS), 8 patients with sickle cell hemoglobin C disease (Hb SC), 13 with homozygote sickle cell anemia (Hb SS) and 7 normal controls (Hb AA) were submitted to Wrong and Davies' acidification test. Renal concentrating capacity and glomerular filtration rate were also estimated. Urinary pH after acid loading was significantly higher, titratable acidity (TA) significantly lower in SC and SS patients compared to AS subjects and normals. NH 4 + excretion did not differ between the four groups. In none of the subjects investigated was metabolic acidosis found, characterizing the acidification defect in sickle cell nephropathy as the incomplete form of renal tubular acidosis (RTA). A correlation between the degree of disturbance in renal acidifying and concentrating capacity could be observed.

Effect of maternal sickle-cell trait on perinatal mortality.

Possession of the sickle-cell trait (Hb AS) by the African mother has been shown to be associated with a significant increase in perinatal mortality when there is anoxic stress. This observation should be taken into consideration in the management of labour of both the indigenous and immigrant mothers at risk. The findings do not influence the proposed explanations for the maintenance of high frequencies of the haemoglobin S gene in areas of endemic malaria.

The removal of heat-damaged and 51Cr-labelled red cells in haemoglobinopathies.

Summary. Fifty‐seven individuals, all living in Ghana, and having Hb types AA (controls), AS, S‐thalassaemia, CC, SC, and SS, were studied using 51Cr‐labelled heatdamaged red cells. Investigations were designed to show the effect of heating on red cell morphology, G6PD activity, osmotic and mechanical fragility, ESR, sickling, and the clearance of the cells from the circulation after injection. In transfusion experiments, damaged cells were given to recipients with differing haemoglobin types and the cell disappearance and radioactive uptake by the liver and spleen were measured. In AS, S‐thalassaemia and CC patients the clearance and splenic uptake were similar to those of the AA subjects. In some of the SC and in all of the SS patients, the spleen did not sequester damaged cells, although they were cleared fairly rapidly from the circulation in a few cases. It was concluded that intracorpuscular factors cannot be ignored in the removal of heat damaged cells from the circulation, even though extracorpuscular mechanisms play the major part.

Fractionation studies of copper in erythrocytes from normal, sickle cell anemia, and hemoglobin C disease.

SummaryQuantitative copper determinations of erythrocyte fractions obtained by ultracentrifugation of erythrocyte homogenates from 105- persons were made by atomic absorption spectrophotometry. Elevated copper levels were demonstrated in the particulate fraction of erythrocytes of 16 patients with sickle cell anemia (Hb SS), 30 patients with sickle cell trait (Hb AS), 14 patients with hemoglobin C trait (Hb AC), and 5 patients with hemoglobin SC, as compared to similar fractions from 40 normal persons (Hb AA). Erythrocytes from sickle cell anemia patients contained sedimentable copper levels approximately twice that of normal controls. The sedimentable copper values from sickle cell trait were 1.5 times that of normal cells. The significance of these findings is discussed.