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Query: UMLS:C0019045 (hemoglobinopathies)
 2,704 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A four-year-old boy admitted for fever and a skin rash was diagnosed as having a rickettsial infection. Regenerative microcytic anemia and enlargement of the spleen were also found. Hemoglobin electrophoresis and a family study disclosed a combination of two heterozygous hemoglobinopathies, i.e., HbO Arab and beta-thalassemia. A male sibling had the same anomalies as the index patient and was free of symptoms.
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PMID:[Association of Hbo Arab/beta-thalassemia discovered fortuitously in 2 brothers]. 161 42

Hemoglobin (Hb) S/beta(+)-thalassemia is a hemoglobinopathy of variable but potentially severe clinical course. The condition is usually confirmed by the presence of a microcytic anemia and elevated levels of Hbs S, F, and A2 by electrophoresis. However, other less common disorders of Hb structure and synthesis may exhibit laboratory findings that mimic Hb S/beta(+)-thalassemia but have a more favorable prognosis. We present a case occurring in a man with clinical and laboratory features that were suggestive of Hb S/beta(+)-thalassemia but with normocythemia. Although nonmicrocytic variants of beta(+)-thalassemia, including concomitant nutritional deficiencies, were considered, high-pressure liquid chromatography revealed nearly all of the patient's fetal Hb to contain only G gamma chains. This pattern is most consistent with the rate but clinically benign condition of Hb S/G gamma-beta(+)-hereditary persistence of fetal Hb, a nondeletional type of hereditary persistence of fetal Hb. We discuss a diagnostic approach to adult Hb A, F, and S conditions, including thalassemias and thalassemia-like syndromes.
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PMID:Differential diagnosis of adult hemoglobin A, F, and S conditions. A case of G gamma-beta(+)-hereditary persistence of fetal hemoglobin. 170 58

Hematologic abnormalities in childhood lead poisoning may be due, in part, to the presence of other disorders, such as iron deficiency or thalassemia minor. In order to reassess increased lead burden as a cause of microcytic anemia, we studied 58 children with class III or IV lead poisoning, normal iron stores, and no inherited hemoglobinopathy. Anemia occurred in 12% and microcytosis in 21% of these children. The combination of anemia and microcytosis was found in only one of 58 patients (2%). When only children with class IV lead poisoning were studied, the occurrence of microcytosis increased to 46%. However, the combination of microcytosis and anemia was found in only one of these 13 more severely affected patients. Microcytic anemia was similarly uncommon in children with either blood lead concentration greater than or equal to 50 microgram/100 ml. These data indicate that microcytosis and anemia occur much less commonly than previously reported in childhood lead poisoning uncomplicated by other hematologic disorders.
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PMID:Reassessment of the microcytic anemia of lead poisoning. 723 54

Mutations within exon 3 of the beta-globin gene are relatively uncommon, and many of these mutations produce a dominant thalassemia-like phenotype. We describe a novel thalassemic hemoglobinopathy caused by a single nucleotide substitution (CTG-->CCG) at codon 114 resulting in a leucine to proline substitution and designate it beta Durham-NC [beta 114 Leu-->Pro]. The mutation producing this thalassemic hemoglobinopathy is located near to the beta Showa-Yakushiji mutation (beta 110 Leu-->Pro). Both of these hemoglobinopathies share similar phenotypic features with moderately severe microcytic anemia. Using computer imaging of the hemoglobin molecule, we examined several reported point mutations within exon 3 of the beta-globin gene. These point mutations cause a single amino acid substitution in the G helix, and result in a thalassemic and/or hemolytic phenotype. Computer imaging of nine separate examples suggests that amino acid substitutions affecting side chains that project into the heme pocket may destabilize the heme moiety within the beta-globin chain, resulting in a thalassemic phenotype. Hemolytic phenotypes may be the result of decreased alpha 1 beta 1 interactions. The beta Durham-NC mutation further characterizes a novel group of thalassemias/hemoglobinopathies that are clinically difficult to identify and require accessory laboratory testing.
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PMID:A novel beta-globin mutation, beta Durham-NC [beta 114 Leu-->Pro], produces a dominant thalassemia-like phenotype. 811 Oct 50

An attempt was made to create an expert system with sufficient accuracy to diagnose classes of anemia and report presumptive diagnoses directly on the hematology form. The system should simulate the processes of human experts who can reliably achieve diagnostic separability by pattern analysis. A hybrid expert system combining rule-based and artificial neural network (ANN) models was constructed to evaluate microcytic anemia in a 3-layered program using hematocrit (HCT), mean corpuscular volume (MCV), and coefficient of variation of cell distribution width (RDWcv) as inputs. These measurements are available as standard output on most hematology analyzers. Three categories of microcytic anemia were considered, iron deficiency (IDA), hemoglobinopathy (HEM), and anemia of chronic disease (ACD). A novel feature of the model is its construction and training using human expert input alone. Model construction is described in detail. The model's performance was evaluated with actual case data. It was successful in correctly classifying 96.5% of 473 documented cases of microcytic anemia and anemia of chronic disease. It thus exhibits sufficient accuracy for it to be considered for use in reporting microcytic anemia diagnoses on hematology forms.
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PMID:An expert system to diagnose anemia and report results directly on hematology forms. 868 71

The chemical identification of variant hemoglobins was largely overtaken by DNA analysis during the last decade, despite remarkable improvement and automation of individual procedures in conventional chemistry. DNA diagnosis has proved more versatile, covering both variant hemoglobin and thalassemia mutations, less labor-demanding, and easier to learn. Protein chemistry is now reserved for some special problems such as post-translational modification (this problem would be covered much better by mass spectrometry), biosynthesis and stability, and pathologic physiology of selected abnormal hemoglobins. After introduction of DNA analysis during mid 1980's, the number of blood samples referred to our laboratory rapidly increased, mainly because of thalassemia traits in the differential diagnosis of microcytic anemia. Our experience during the past forty years and the present strategy for the rapid presumptive diagnosis of hemoglobinopathies and precise identification of mutations are briefly summarized.
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PMID:[Diagnosis of hemoglobinopathies]. 962 95

Anemia in children is commonly encountered by the family physician. Multiple causes exist, but with a thorough history, a physical examination and limited laboratory evaluation a specific diagnosis can usually be established. The use of the mean corpuscular volume to classify the anemia as microcytic, normocytic or macrocytic is a standard diagnostic approach. The most common form of microcytic anemia is iron deficiency caused by reduced dietary intake. It is easily treatable with supplemental iron and early intervention may prevent later loss of cognitive function. Less common causes of microcytosis are thalassemia and lead poisoning. Normocytic anemia has many causes, making the diagnosis more difficult. The reticulocyte count will help narrow the differential diagnosis; however, additional testing may be necessary to rule out hemolysis, hemoglobinopathies, membrane defects and enzymopathies. Macrocytic anemia may be caused by a deficiency of folic acid and/or vitamin B12, hypothyroidism and liver disease. This form of anemia is uncommon in children.
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PMID:Anemia in children. 1168 80

Sickle-beta(+) (beta(+)) thalassemia is a double heterozygous genetic disorder characterized by both a qualitative and quantitative abnormality. We present a case of an African American male who was first diagnosed with sickle cell disease (SCD) at the age 23 years when he presented with generalized bone pain, fever, and hepatosplenomegaly. Laboratory findings included thrombocytopenia, microcytic anemia, and markedly elevated ferritin. He was subsequently diagnosed with a sickle-beta thalassemia hemoglobinopathy. Findings in the bone marrow aspirate and biopsy were consistent with hemophagocytic lymphohistiocytosis (HLH). HLH resolved with the resolution of sickle cell bone pain crisis without use of immunosuppressive therapy. To the best of our knowledge this is the first documented case of HLH associated with sickle cell bone pain crisis.
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PMID:Sickle cell crisis associated with hemophagocytic lymphohistiocytosis. 1549 57

In the majority of cases, microcytosis is the result of impaired hemoglobin synthesis. Disorders of iron metabolism and protoporphyrin and heme synthesis, as well as impaired globin synthesis, lead to defective hemoglobin production and to the generation of microcytosis and microcytic anemia. Iron deficiency anemie, anemia of chronic diseases, thalassemias, congenital sideroblastic anemias and homozygous HbE disease are the main representatives of microcytosis and microcytic anemias. Serum iron, total iron binding capacity, transferrin saturation, serum ferritin, serum transferrin receptor, transferrin receptor-ferritin index, and zinc-protoporhyrin concentration in erythrocytes are tests used for assessment of iron deficiency. The convention laboratory test for diagnosing iron deficiency is the measurement of serum ferritin. The most precise method for evaluating body iron stores is the examination for iron on aspirated bone marrow or marrow biopsy. Increased content of Hb A2 over 3.5% is diagnostic for beta-thalassemia. Presence of ringed sideroblasts is characteristic of sideroblastic anemias. Hemoglobin electrophoresis is required for the diagnosis of hemoglobinopathy E. The optimal therapeutic regimen in iron deficiency anemia used in this country is to administer 100 mg of elemental iron twice daily separately from meals. Ferrous sulphate (Ferronat Retard tbl. or Sorbifer Dulures tbl.) which are slow-releasing iron formulations are preferred because of their low cost, high bioavailability and low side-effects. Parenteral iron therapy is justified only in patients who cannot absorb iron, who have blood losses that exceed the maximal absorptive capacity of their intestinal tract or who are totally intolerant of oral iron. However, parenteral iron therapy may be associated with serious and even fatal side-effects.
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PMID:[Microcytic and hypochromic anemias]. 1563 79

A Thai family with a complex thalassemia syndrome caused by alpha- and beta-globin defects is described. The proband was a 14-year-old boy who had chronic hypochromic microcytic anemia. Hemoglobin (Hb) and DNA analyses demonstrated that he carried Hb Beijing [alpha16(A14)Lys-->Asn], Hb E [beta26(B8)Glu-->Lys] and alpha-thalassemia-1 (alpha-thal-1). Interaction of the alphaBeijing with the betaE globin chains in the proband leads to a new Hb variant, namely Hb E Beijing with different characteristics to both Hb E and Hb Beijing. Family studies showed that his father carried Hb Beijing and Hb E, whereas his mother was a simple alpha-thal-1 carrier. The genotype-phenotype relationship observed in this Thai family with complex hemoglobinopathies is presented and a simple DNA assay based on allele specific polymerase chain reaction (ASPCR) for detection of Hb Beijing is described.
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PMID:Thalassemia intermedia associated with complex interaction of Hb Beijing [alpha16(A14)Lys-->Asn] and Hb E [beta26(B8)Glu-->Lys] with a deletional alpha-thalassemia-1 in a Thai family. 1576 59


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