Screening For Abnormal Hemoglobins Research Articles

A Case of Inappropriately High Glycated Hemoglobin

Hemoglobin is a tetramer formed of two alpha and two beta globin chains. On exposure to high levels of blood glucose, hemoglobin gets non-enzymatically glycated at different sites in the molecule. HbA1c is formed when glucose gets added on to the N-terminal valine residue of the beta chain of hemoglobin. The development of chronic vascular complications of diabetes such as retinopathy, nephropathy and cardiovascular disease is intimately linked to the level of glycemic control attained by the individual with diabetes. We report a case of convulsions and monoplegia admitted to emergency department, showing unusually high glycated hemoglobin but plasma glucose not as high. The patient was not a known diabetic and we could not find any of the other documented conditions that are known to elevate glycated hemoglobin to such disproportionately high levels. Screening for abnormal hemoglobins was negative in the patient. Oral hypoglycemic drug treatment over 3months and withdrawal of other medications only marginally lowered glycated hemoglobin.

A New, Electrophoretically Silent, Fetal Hemoglobin Variant: Hb F-Calabria [Gγ118(GH1)Phe→Leu

Hb F-Calabria [Gγ118(GH1)Phe→Leu] is a new fetal hemoglobin variant that was found during routine screening for abnormal hemoglobins in a newborn of Calabrian (Southern Italy) ancestry. the variant chain was identified (acid urea gel elect rophoresis of dissociated globin chains in the presence of Triton X-100, and by reversed phase high performance liquid chromatography) as a slightly hydrophilic Gγ chain. Sequencing of the polymerase chain reaction-amplified exon 3 of the Gγ-globin gene demonstrated the TTC→CTC mutation at codon 118 leading to the Phe→Leu conservative substitution at position GH1. A molecular modeling study supports that the variant might not have clinical implications. This is the 40th example of a Gγ chain variant.

Screening for Abnormal Hemoglobins: Who, When, and How

Sickle cell and abnormal hemoglobin screening programs should not be undertaken lightly but rather should have a specific purpose or purposes. If the aim is to detect only sickle hemoglobin, a certain strategy is necessary. If the goal is to detect all abnormal hemoglobins and genetic counseling is planned, another approach should be used. A simple solubility test detects sickle hemoglobin with high reliability, but deals with no other abnormal hemoglobins. Hemoglobin electrophoresis, followed by other tests as indicated, is then necessary to ascertain other abnormal hemoglobins in addition to hemoglobin S.

Double heterozygosity for hemoglobin Camden (beta131 Gln replaced by Glu) and alpha thalassemia.

During the course o f screening for abnormal hemoglobins in the City of New York, an abnormal hemoglobin with fast electrophoretic mobility was discovered in an asymptomatic 16-year-old Black female high school student. Structural studies, performed on the variant hemoglobin, demonstrated an amino acid substitution (B131 Gln → Glu) which has been described previously as hemoglobin Camden (1,2,3). studies were indicated by the observation of approximately 45% Hb Camden in association with mild microcytosis and hypochromia, perhaps the suggestion of α-thalassemia.

Haemoglobin J Guantanamo ( [formula omitted]) A new fast unstable haemoglobin found in a Cuban family

Haemoglobin J Guantanamo ( α 2β 2128( H6) Ala a ̊ Asp ) was found during a screening for abnormal haemoglobins in three members of a Cuban family, of negro ancestry. The substitution in this variant is located at the α 1 β 1 contact. This explains the slight instability and the mild haemolytic anaemia and morphological abnormalities found in the carriers of this variant. The instability of haemoglobin J Guantanamo indicates that the presence of Asp at the position β-128(H6) weakens the α 1 β 1 contact.

Use of blood specimens collected on filter paper in screening for abnormal hemoglobins.

Both cellulose acetate electrophoresis and citrate agar electrophoresis were performed on 834 blood samples collected on filter paper in Jamaica and shipped for testing to the National Hemoglobinopathy Standardization Laboratory at the U.S. National Center for Disease Control. Additionally, 30 blood samples collected locally were stored on filter paper, in microhematocrit capillary tubes, and as whole blood specimens; at selected times the samples were tested for stability to determine the best sample-collection technique for hemoglobin electrophoresis. Results were most nearly accurate when both cellulose acetate electrophoresis and citrate agar testing were used. The methods are easy to perform, but results are unreliable if the blood samples on filter paper are stored at 4 degrees C for longer than two weeks before they are tested.

Screening for abnormal hemoglobins in the middle east: new data on hemoglobin S and the presence of hemoglobin C in Saudi Arabia.

48 of 391 apparently healthy adult Saudi males had an AS hemoglobin pattern on electrophoresis, four subjects had an S pattern, and two subjects AC. A dithionite screening test lacked sensitivity and specificity in detecting hemoglobin S under the conditions of this study. A sickle cell trait frequency of 0.123 evidenced by hemoglobin electrophoresis correlates closely with previous studies of hemoglobinopathies in Saudi Arabs. The presence of four subjects with sickle cell disease in the study group provides further evidence of the "benign" nature of sickle cell disease in Saudi Arabia.

Proceedings: Screening for abnormal haemoglobins in the immigrant community.

Proceedings: Screening for abnormal haemoglobins in the immigrant community.

Genetic and clinical relevance of haemoglobins screening: Results from a survey in a paediatric hospital

A screening for abnormal haemoglobins was carried out on the patients admitted to a Childrens Hospital during a 16‐month period using a rapid electrophoretic technique, with the purpose of finding the prevalence of HbS carriers. The results of this study show that the Cuban population has a high percentage of heterozygotes for HbS. The importance of such a screening for medical care is discussed.The frequency of abnormal “rare” haemoglobins found during the course of this survey is also given.