Thalassemia: A group of hereditary hemolytic anemias in which there is decreased synthesis of one or more hemoglobin polypeptide chains. There are several genetic types with clinical pictures ranging from barely detectable hematologic abnormality to severe and fatal anemia.beta-Thalassemia: A disorder characterized by reduced synthesis of the beta chains of hemoglobin. There is retardation of hemoglobin A synthesis in the heterozygous form (thalassemia minor), which is asymptomatic, while in the homozygous form (thalassemia major, Cooley's anemia, Mediterranean anemia, erythroblastic anemia), which can result in severe complications and even death, hemoglobin A synthesis is absent.Hemoglobin E: An abnormal hemoglobin that results from the substitution of lysine for glutamic acid at position 26 of the beta chain. It is most frequently observed in southeast Asian populations.alpha-Thalassemia: A disorder characterized by reduced synthesis of the alpha chains of hemoglobin. The severity of this condition can vary from mild anemia to death, depending on the number of genes deleted.Fetal Hemoglobin: The major component of hemoglobin in the fetus. This HEMOGLOBIN has two alpha and two gamma polypeptide subunits in comparison to normal adult hemoglobin, which has two alpha and two beta polypeptide subunits. Fetal hemoglobin concentrations can be elevated (usually above 0.5%) in children and adults affected by LEUKEMIA and several types of ANEMIA.Globins: A superfamily of proteins containing the globin fold which is composed of 6-8 alpha helices arranged in a characterstic HEME enclosing structure.Hemoglobinopathies: A group of inherited disorders characterized by structural alterations within the hemoglobin molecule.Hemoglobin A2: An adult hemoglobin component normally present in hemolysates from human erythrocytes in concentrations of about 3%. The hemoglobin is composed of two alpha chains and two delta chains. The percentage of HbA2 varies in some hematologic disorders, but is about double in beta-thalassemia.alpha-Globins: Members of the alpha-globin family. In humans, they are encoded in a gene cluster on CHROMOSOME 16. They include zeta-globin and alpha-globin. There are also pseudogenes of zeta (theta-zeta) and alpha (theta-alpha) in the cluster. Adult HEMOGLOBIN is comprised of 2 alpha-globin chains and 2 beta-globin chains.Chelation Therapy: Therapy of heavy metal poisoning using agents which sequester the metal from organs or tissues and bind it firmly within the ring structure of a new compound which can be eliminated from the body.Hemoglobin J: A group of abnormal hemoglobins with similar electrophoretic characteristics. They have faster electrophoretic mobility and different amino acid substitutions in either the alpha or beta chains than normal adult hemoglobin. Some of the variants produce hematologic abnormalities, others result in no clinical disorders.SicilyArabia: The great peninsula of southwest Asia comprising most of the present countries of the Middle East. It has been known since the first millennium B.C. In early times it was divided into Arabia Petraea, the northwest part, the only part ever conquered, becoming a Roman province; Arabia Deserta, the northern part between Syria and Mesopotamia; and Arabia Felix, the main part of the peninsula but by some geographers restricted to modern Yemen. (From Webster's New Geographical Dictionary, 1988, p63)Hemoglobins, Abnormal: Hemoglobins characterized by structural alterations within the molecule. The alteration can be either absence, addition or substitution of one or more amino acids in the globin part of the molecule at selected positions in the polypeptide chains.Hemoglobin A: Normal adult human hemoglobin. The globin moiety consists of two alpha and two beta chains.Iron Overload: An excessive accumulation of iron in the body due to a greater than normal absorption of iron from the gastrointestinal tract or from parenteral injection. This may arise from idiopathic hemochromatosis, excessive iron intake, chronic alcoholism, certain types of refractory anemia, or transfusional hemosiderosis. (From Churchill's Illustrated Medical Dictionary, 1989)Hemoglobinometry: Measurement of hemoglobin concentration in blood.Erythrocytes, Abnormal: Oxygen-carrying RED BLOOD CELLS in mammalian blood that are abnormal in structure or function.Blood Transfusion: The introduction of whole blood or blood component directly into the blood stream. (Dorland, 27th ed)Anemia, Sickle Cell: A disease characterized by chronic hemolytic anemia, episodic painful crises, and pathologic involvement of many organs. It is the clinical expression of homozygosity for hemoglobin S.Homozygote: An individual in which both alleles at a given locus are identical.Hemoglobins: The oxygen-carrying proteins of ERYTHROCYTES. They are found in all vertebrates and some invertebrates. The number of globin subunits in the hemoglobin quaternary structure differs between species. Structures range from monomeric to a variety of multimeric arrangements.Erythrocyte Count: The number of RED BLOOD CELLS per unit volume in a sample of venous BLOOD.Erythrocyte Indices: ERYTHROCYTE size and HEMOGLOBIN content or concentration, usually derived from ERYTHROCYTE COUNT; BLOOD hemoglobin concentration; and HEMATOCRIT. The indices include the mean corpuscular volume (MCV), the mean corpuscular hemoglobin (MCH), and the mean corpuscular hemoglobin concentration (MCHC).Heterozygote Detection: Identification of genetic carriers for a given trait.Reticulocytes: Immature ERYTHROCYTES. In humans, these are ERYTHROID CELLS that have just undergone extrusion of their CELL NUCLEUS. They still contain some organelles that gradually decrease in number as the cells mature. RIBOSOMES are last to disappear. Certain staining techniques cause components of the ribosomes to precipitate into characteristic "reticulum" (not the same as the ENDOPLASMIC RETICULUM), hence the name reticulocytes.Erythropoiesis: The production of red blood cells (ERYTHROCYTES). In humans, erythrocytes are produced by the YOLK SAC in the first trimester; by the liver in the second trimester; by the BONE MARROW in the third trimester and after birth. In normal individuals, the erythrocyte count in the peripheral blood remains relatively constant implying a balance between the rate of erythrocyte production and rate of destruction.Ferritins: Iron-containing proteins that are widely distributed in animals, plants, and microorganisms. Their major function is to store IRON in a nontoxic bioavailable form. Each ferritin molecule consists of ferric iron in a hollow protein shell (APOFERRITINS) made of 24 subunits of various sequences depending on the species and tissue types.Iron Chelating Agents: Organic chemicals that form two or more coordination links with an iron ion. Once coordination has occurred, the complex formed is called a chelate. The iron-binding porphyrin group of hemoglobin is an example of a metal chelate found in biological systems.Splenectomy: Surgical procedure involving either partial or entire removal of the spleen.Heterozygote: An individual having different alleles at one or more loci regarding a specific character.Erythrocytes: Red blood cells. Mature erythrocytes are non-nucleated, biconcave disks containing HEMOGLOBIN whose function is to transport OXYGEN.Erythrocyte Membrane: The semi-permeable outer structure of a red blood cell. It is known as a red cell 'ghost' after HEMOLYSIS.Deferoxamine: Natural product isolated from Streptomyces pilosus. It forms iron complexes and is used as a chelating agent, particularly in the mesylate form.5'-Nucleotidase: A glycoprotein enzyme present in various organs and in many cells. The enzyme catalyzes the hydrolysis of a 5'-ribonucleotide to a ribonucleoside and orthophosphate in the presence of water. It is cation-dependent and exists in a membrane-bound and soluble form. EC 18.104.22.168.Pyridones: Pyridine derivatives with one or more keto groups on the ring.Interleukin-1beta: An interleukin-1 subtype that is synthesized as an inactive membrane-bound pro-protein. Proteolytic processing of the precursor form by CASPASE 1 results in release of the active form of interleukin-1beta from the membrane.beta-Globins: Members of the beta-globin family. In humans, they are encoded in a gene cluster on CHROMOSOME 11. They include epsilon-globin, gamma-globin, delta-globin and beta-globin. There is also a pseudogene of beta (theta-beta) in the gene cluster. Adult HEMOGLOBIN is comprised of two ALPHA-GLOBIN chains and two beta-globin chains.Base Sequence: The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.Hemoglobin H: An abnormal hemoglobin composed of four beta chains. It is caused by the reduced synthesis of the alpha chain. This abnormality results in ALPHA-THALASSEMIA.Mutation: Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.beta 2-Microglobulin: An 11-kDa protein associated with the outer membrane of many cells including lymphocytes. It is the small subunit of the MHC class I molecule. Association with beta 2-microglobulin is generally required for the transport of class I heavy chains from the endoplasmic reticulum to the cell surface. Beta 2-microglobulin is present in small amounts in serum, csf, and urine of normal people, and to a much greater degree in the urine and plasma of patients with tubular proteinemia, renal failure, or kidney transplants.Iron: A metallic element with atomic symbol Fe, atomic number 26, and atomic weight 55.85. It is an essential constituent of HEMOGLOBINS; CYTOCHROMES; and IRON-BINDING PROTEINS. It plays a role in cellular redox reactions and in the transport of OXYGEN.Bone Marrow Transplantation: The transference of BONE MARROW from one human or animal to another for a variety of purposes including HEMATOPOIETIC STEM CELL TRANSPLANTATION or MESENCHYMAL STEM CELL TRANSPLANTATION.Phenotype: The outward appearance of the individual. It is the product of interactions between genes, and between the GENOTYPE and the environment.IndiaSickle Cell Trait: The condition of being heterozygous for hemoglobin S.Receptors, Adrenergic, beta: One of two major pharmacologically defined classes of adrenergic receptors. The beta adrenergic receptors play an important role in regulating CARDIAC MUSCLE contraction, SMOOTH MUSCLE relaxation, and GLYCOGENOLYSIS.Integrin beta3: An integrin beta subunit of approximately 85-kDa in size which has been found in INTEGRIN ALPHAIIB-containing and INTEGRIN ALPHAV-containing heterodimers. Integrin beta3 occurs as three alternatively spliced isoforms, designated beta3A-C.Hemosiderosis: Conditions in which there is a generalized increase in the iron stores of body tissues, particularly of liver and the MONONUCLEAR PHAGOCYTE SYSTEM, without demonstrable tissue damage. The name refers to the presence of stainable iron in the tissue in the form of hemosiderin.delta-Thalassemia: A hereditary disorder characterized by reduced or absent DELTA-GLOBIN thus effecting the level of HEMOGLOBIN A2, a minor component of adult hemoglobin monitored in the diagnosis of BETA-THALASSEMIA.Hemoglobin, Sickle: An abnormal hemoglobin resulting from the substitution of valine for glutamic acid at position 6 of the beta chain of the globin moiety. The heterozygous state results in sickle cell trait, the homozygous in sickle cell anemia.Transforming Growth Factor beta: A factor synthesized in a wide variety of tissues. It acts synergistically with TGF-alpha in inducing phenotypic transformation and can also act as a negative autocrine growth factor. TGF-beta has a potential role in embryonal development, cellular differentiation, hormone secretion, and immune function. TGF-beta is found mostly as homodimer forms of separate gene products TGF-beta1, TGF-beta2 or TGF-beta3. Heterodimers composed of TGF-beta1 and 2 (TGF-beta1.2) or of TGF-beta2 and 3 (TGF-beta2.3) have been isolated. The TGF-beta proteins are synthesized as precursor proteins.Anemia, Hypochromic: Anemia characterized by a decrease in the ratio of the weight of hemoglobin to the volume of the erythrocyte, i.e., the mean corpuscular hemoglobin concentration is less than normal. The individual cells contain less hemoglobin than they could have under optimal conditions. Hypochromic anemia may be caused by iron deficiency from a low iron intake, diminished iron absorption, or excessive iron loss. It can also be caused by infections or other diseases, therapeutic drugs, lead poisoning, and other conditions. (Stedman, 25th ed; from Miale, Laboratory Medicine: Hematology, 6th ed, p393)Osmotic Fragility: RED BLOOD CELL sensitivity to change in OSMOTIC PRESSURE. When exposed to a hypotonic concentration of sodium in a solution, red cells take in more water, swell until the capacity of the cell membrane is exceeded, and burst.Hemoglobin C: A commonly occurring abnormal hemoglobin in which lysine replaces a glutamic acid residue at the sixth position of the beta chains. It results in reduced plasticity of erythrocytes.Hematopoiesis, Extramedullary: The formation and development of blood cells outside the BONE MARROW, as in the SPLEEN; LIVER; or LYMPH NODES.RNA, Messenger: RNA sequences that serve as templates for protein synthesis. Bacterial mRNAs are generally primary transcripts in that they do not require post-transcriptional processing. Eukaryotic mRNA is synthesized in the nucleus and must be exported to the cytoplasm for translation. Most eukaryotic mRNAs have a sequence of polyadenylic acid at the 3' end, referred to as the poly(A) tail. The function of this tail is not known for certain, but it may play a role in the export of mature mRNA from the nucleus as well as in helping stabilize some mRNA molecules by retarding their degradation in the cytoplasm.Integrin alpha5beta1: An integrin found in FIBROBLASTS; PLATELETS; MONOCYTES, and LYMPHOCYTES. Integrin alpha5beta1 is the classical receptor for FIBRONECTIN, but it also functions as a receptor for LAMININ and several other EXTRACELLULAR MATRIX PROTEINS.Integrin beta4: Also known as CD104 antigen, this protein is distinguished from other beta integrins by its relatively long cytoplasmic domain (approximately 1000 amino acids vs. approximately 50). Five alternatively spliced isoforms have been described.ItalyIntegrin alpha6beta4: This intrgrin is a key component of HEMIDESMOSOMES and is required for their formation and maintenance in epithelial cells. Integrin alpha6beta4 is also found on thymocytes, fibroblasts, and Schwann cells, where it functions as a laminin receptor (RECEPTORS, LAMININ) and is involved in wound healing, cell migration, and tumor invasiveness.delta-Globins: A member of the beta-globin family. In humans, delta-globin is encoded in the beta-globin gene cluster located on CHROMOSOME 11. Two delta-globin chains along with two alpha-globin chains form HEMOGLOBIN A2 which makes up about 3% of the HEMOGLOBIN in adults.Integrin beta Chains: Integrin beta chains combine with integrin alpha chains to form heterodimeric cell surface receptors. Integrins have traditionally been classified into functional groups based on the identity of one of three beta chains present in the heterodimer. The beta chain is necessary and sufficient for integrin-dependent signaling. Its short cytoplasmic tail contains sequences critical for inside-out signaling.Benzoates: Derivatives of BENZOIC ACID. Included under this heading are a broad variety of acid forms, salts, esters, and amides that contain the carboxybenzene structure.beta 2-Glycoprotein I: A 44-kDa highly glycosylated plasma protein that binds phospholipids including CARDIOLIPIN; APOLIPOPROTEIN E RECEPTOR; membrane phospholipids, and other anionic phospholipid-containing moieties. It plays a role in coagulation and apoptotic processes. Formerly known as apolipoprotein H, it is an autoantigen in patients with ANTIPHOSPHOLIPID ANTIBODIES.Erythrocyte Aging: The senescence of RED BLOOD CELLS. Lacking the organelles that make protein synthesis possible, the mature erythrocyte is incapable of self-repair, reproduction, and carrying out certain functions performed by other cells. This limits the average life span of an erythrocyte to 120 days.Electronics, Medical: The research and development of ELECTRICAL EQUIPMENT AND SUPPLIES for such medical applications as diagnosis, therapy, research, anesthesia control, cardiac control, and surgery. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)Integrin alpha4beta1: Integrin alpha4beta1 is a FIBRONECTIN and VCAM-1 receptor present on LYMPHOCYTES; MONOCYTES; EOSINOPHILS; NK CELLS and thymocytes. It is involved in both cell-cell and cell- EXTRACELLULAR MATRIX adhesion and plays a role in INFLAMMATION, hematopoietic cell homing and immune function, and has been implicated in skeletal MYOGENESIS; NEURAL CREST migration and proliferation, lymphocyte maturation and morphogenesis of the PLACENTA and HEART.Anemia: A reduction in the number of circulating ERYTHROCYTES or in the quantity of HEMOGLOBIN.Hemoglobin C Disease: A disease characterized by compensated hemolysis with a normal hemoglobin level or a mild to moderate anemia. There may be intermittent abdominal discomfort, splenomegaly, and slight jaundice.Genes: A category of nucleic acid sequences that function as units of heredity and which code for the basic instructions for the development, reproduction, and maintenance of organisms.Hemoglobin SC Disease: One of the sickle cell disorders characterized by the presence of both hemoglobin S and hemoglobin C. It is similar to, but less severe than sickle cell anemia.Melanesia: The collective name for the islands of the Pacific Ocean northeast of Australia, including NEW CALEDONIA; VANUATU; New Hebrides, Solomon Islands, Admiralty Islands, Bismarck Archipelago, FIJI, etc. Melanesia (from the Greek melas, black + nesos, island) is so called from the black color of the natives who are generally considered to be descended originally from the Negroid Papuans and the Polynesians or Malays. (From Webster's New Geographical Dictionary, 1988, p748 & Room, Brewer's Dictionary of Names, 1992, p344)Integrin alpha2beta1: An integrin found on fibroblasts, platelets, endothelial and epithelial cells, and lymphocytes where it functions as a receptor for COLLAGEN and LAMININ. Although originally referred to as the collagen receptor, it is one of several receptors for collagen. Ligand binding to integrin alpha2beta1 triggers a cascade of intracellular signaling, including activation of p38 MAP kinase.Receptors, Adrenergic, beta-2: A subclass of beta-adrenergic receptors (RECEPTORS, ADRENERGIC, BETA). The adrenergic beta-2 receptors are more sensitive to EPINEPHRINE than to NOREPINEPHRINE and have a high affinity for the agonist TERBUTALINE. They are widespread, with clinically important roles in SKELETAL MUSCLE; LIVER; and vascular, bronchial, gastrointestinal, and genitourinary SMOOTH MUSCLE.