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Hemoglobin Constant Spring
Hemoglobin Constant Spring is a variant of hemoglobin in which a mutation in the alpha globin gene produces an alpha globin chain that is abnormally long. It is the most common nondeletional alpha-thalassemia mutation associated with hemoglobin H disease. The quantity of hemoglobin in the cells is low because the messenger RNA is unstable and some is degraded prior to protein synthesis. Another reason is that the Constant Spring alpha chain protein is itself unstable. The result is a thalassemic phenotype. Hemoglobin Constant Spring is renamed after Constant Spring district in Jamaica. See also * Hemoglobin variants * Hemoglobinopathy Hemoglobinopathy is the medical term for a group of inherited blood disorders and diseases that primarily affect red blood cells. They are single-gene disorders and, in most cases, they are inherited as autosomal co-dominant traits. There are t ... * Thalassemia References {{Reflist Hemoglobins ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hemoglobin Variants
Hemoglobin variants are mutant forms of hemoglobin in a population, caused by variations in genetics. Some well-known hemoglobin variants such as sickle-cell anemia Sickle cell disease (SCD) is a group of blood disorders typically inherited from a person's parents. The most common type is known as sickle cell anaemia. It results in an abnormality in the oxygen-carrying protein haemoglobin found in red bl ... are responsible for diseases, and are considered hemoglobinopathies. Other variants cause no detectable pathology, and are thus considered non-pathological variants. Some normal hemoglobin types are; Hemoglobin A (Hb A), which is 95–98% of hemoglobin found in adults, Hemoglobin A2 (Hb A2), which is 2–3% of hemoglobin found in adults, and Hemoglobin F (Hb F), which is found in adults up to 2.5% and is the primary hemoglobin that is produced by the fetus during pregnancy. Hemoglobin variants occur when there are genetic changes in specific genes, or globins, that ca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hemoglobin
Hemoglobin (haemoglobin BrE) (from the Greek word αἷμα, ''haîma'' 'blood' + Latin ''globus'' 'ball, sphere' + ''-in'') (), abbreviated Hb or Hgb, is the iron-containing oxygen-transport metalloprotein present in red blood cells (erythrocytes) of almost all vertebrates (the exception being the fish family Channichthyidae) as well as the tissues of some invertebrates. Hemoglobin in blood carries oxygen from the respiratory organs (''e.g.'' lungs or gills) to the rest of the body (''i.e.'' tissues). There it releases the oxygen to permit aerobic respiration to provide energy to power functions of an organism in the process called metabolism. A healthy individual human has 12to 20grams of hemoglobin in every 100mL of blood. In mammals, the chromoprotein makes up about 96% of the red blood cells' dry content (by weight), and around 35% of the total content (including water). Hemoglobin has an oxygen-binding capacity of 1.34mL O2 per gram, which increases the total blood oxygen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mutation
In biology, a mutation is an alteration in the nucleic acid sequence of the genome of an organism, virus, or extrachromosomal DNA. Viral genomes contain either DNA or RNA. Mutations result from errors during DNA or viral replication, mitosis, or meiosis or other types of damage to DNA (such as pyrimidine dimers caused by exposure to ultraviolet radiation), which then may undergo error-prone repair (especially microhomology-mediated end joining), cause an error during other forms of repair, or cause an error during replication (translesion synthesis). Mutations may also result from insertion or deletion of segments of DNA due to mobile genetic elements. Mutations may or may not produce detectable changes in the observable characteristics (phenotype) of an organism. Mutations play a part in both normal and abnormal biological processes including: evolution, cancer, and the development of the immune system, including junctional diversity. Mutation is the ultimate source o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alpha Globin
Hemoglobin subunit alpha, Hemoglobin, alpha 1, is a hemoglobin protein that in humans is encoded by the ''HBA1'' gene. Gene The human alpha globin gene cluster located on chromosome 16 spans about 30 kb and includes seven loci: 5'- zeta - pseudozeta - mu - pseudoalpha-1 - alpha-2 - alpha-1 - theta - 3'. The alpha-2 (HBA2) and alpha-1 (HBA1; this gene) coding sequences are identical. These genes differ slightly over the 5' untranslated regions and the introns, but they differ significantly over the 3' untranslated regions. Protein Two alpha chains plus two beta chains constitute HbA, which in normal adult life comprises about 97% of the total hemoglobin; alpha chains combine with delta chains to constitute HbA-2, which with fetal hemoglobin (HbF) makes up the remaining 3% of adult hemoglobin. Clinical significance Alpha thalassemias result from deletions of each of the alpha genes as well as deletions of both HBA2 and HBA1; some nondeletion alpha thalassemias have also ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gene
In biology, the word gene (from , ; "...Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a basic unit of heredity and the molecular gene is a sequence of nucleotides in DNA that is transcribed to produce a functional RNA. There are two types of molecular genes: protein-coding genes and noncoding genes. During gene expression, the DNA is first copied into RNA. The RNA can be directly functional or be the intermediate template for a protein that performs a function. The transmission of genes to an organism's offspring is the basis of the inheritance of phenotypic traits. These genes make up different DNA sequences called genotypes. Genotypes along with environmental and developmental factors determine what the phenotypes will be. Most biological traits are under the influence of polygenes (many different genes) as well as gen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alpha-thalassemia
Alpha-thalassemia (α-thalassemia, α-thalassaemia) is a form of thalassemia involving the genes ''HBA1'' and ''HBA2''. Thalassemias are a group of inherited blood conditions which result in the impaired production of hemoglobin, the molecule that carries oxygen in the blood. Normal hemoglobin consists of two alpha chains and two beta chains; in alpha-thalassemia, there is a quantitative decrease in the amount of alpha chains, resulting in fewer normal hemoglobin molecules. Furthermore, alpha-thalassemia leads to the production of unstable beta globin molecules which cause increased red blood cell destruction. The degree of impairment is based on which clinical phenotype is present (how many genes are affected). Signs and symptoms The presentation of individuals with alpha-thalassemia consists of: Cause Alpha-thalassemias are most commonly inherited in a Mendelian recessive manner. They are also associated with deletions of chromosome 16p. Alpha thalassemia can also be acqu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hemoglobin H
Hemoglobin H disease is a type of alpha thalassemia caused by impaired production of three of the four alpha globins, coded by genes HBA1 and HBA2. See also * Hemoglobin Barts Hemoglobin Barts, abbreviated Hb Barts, is an abnormal type of hemoglobin that consists of four gamma globins. It is moderately insoluble, and therefore accumulates in the red blood cells. Hb Barts has an extremely high affinity for oxygen, so it ... References External links Blood disorders {{Circulatory-disease-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Messenger RNA
In molecular biology, messenger ribonucleic acid (mRNA) is a single-stranded molecule of RNA that corresponds to the genetic sequence of a gene, and is read by a ribosome in the process of synthesizing a protein. mRNA is created during the process of transcription, where an enzyme (RNA polymerase) converts the gene into primary transcript mRNA (also known as pre-mRNA). This pre-mRNA usually still contains introns, regions that will not go on to code for the final amino acid sequence. These are removed in the process of RNA splicing, leaving only exons, regions that will encode the protein. This exon sequence constitutes mature mRNA. Mature mRNA is then read by the ribosome, and, utilising amino acids carried by transfer RNA (tRNA), the ribosome creates the protein. This process is known as translation. All of these processes form part of the central dogma of molecular biology, which describes the flow of genetic information in a biological system. As in DNA, genetic inf ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Constant Spring, Jamaica
Constant Spring is a residential neighbourhood in the north of Kingston, Jamaica. Constant Spring plantation Constant Spring plantation was one of the Regimental Plantations. It was developed by Lt.-Colonel Henry Archibold during the military occupation following the English invasion of Jamaica. Commander William Brayne described it as "one of the best plantations in the island". Popular culture Constant Spring is referred to in a string of mid-1970s songs, Trinity's "Three Piece Suit and Thing", Lee Perry and Junior Dread's "Sufferer's Heights", and Althea and Donna's "Uptown Top Ranking "Uptown Top Ranking" is a song by Jamaican teenage singers Althea Forrest and Donna Reid, recorded when they were 17 and 18 years old respectively. Released in 1977, the song comprises the girls ad-libbing to deejay track "Three Piece Suit" by T ...". References Neighbourhoods in Kingston, Jamaica Populated places in Saint Andrew Parish, Jamaica {{Settlements in Jamaica, state= ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jamaica
Jamaica (; ) is an island country situated in the Caribbean Sea. Spanning in area, it is the third-largest island of the Greater Antilles and the Caribbean (after Cuba and Hispaniola). Jamaica lies about south of Cuba, and west of Hispaniola (the island containing the countries of Haiti and the Dominican Republic); the British Overseas Territory of the Cayman Islands lies some to the north-west. Originally inhabited by the indigenous Taíno peoples, the island came under Spanish rule following the arrival of Christopher Columbus in 1494. Many of the indigenous people either were killed or died of diseases, after which the Spanish brought large numbers of African slaves to Jamaica as labourers. The island remained a possession of Spain until 1655, when England (later Great Britain) conquered it, renaming it ''Jamaica''. Under British colonial rule Jamaica became a leading sugar exporter, with a plantation economy dependent on the African slaves and later their des ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hemoglobinopathy
Hemoglobinopathy is the medical term for a group of inherited blood disorders and diseases that primarily affect red blood cells. They are single-gene disorders and, in most cases, they are inherited as autosomal co-dominant traits. There are two main groups: abnormal structural hemoglobin variants caused by mutations in the hemoglobin genes, and the thalassemias, which are caused by an underproduction of otherwise normal hemoglobin molecules. The main structural hemoglobin variants are HbS, HbE and HbC. The main types of thalassemia are alpha-thalassemia and beta thalassemia. The two conditions may overlap because some conditions which cause abnormalities in hemoglobin proteins also affect their production. Some hemoglobin variants do not cause pathology or anemia, and thus are often not classed as hemoglobinopathies. Hemoglobin structural biology Normal human hemoglobins are tetrameric proteins composed of two pairs of globin chains, each of which contains one alpha-lik ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thalassemia
Thalassemias are inherited blood disorders characterized by decreased hemoglobin production. Symptoms depend on the type and can vary from none to severe. Often there is mild to severe anemia (low red blood cells or hemoglobin). Anemia can result in feeling tired and pale skin. There may also be bone problems, an enlarged spleen, yellowish skin, and dark urine. Slow growth may occur in children. Thalassemias are genetic disorders inherited from a person's parents. There are two main types, alpha thalassemia and beta thalassemia. The severity of alpha and beta thalassemia depends on how many of the four genes for alpha globin or two genes for beta globin are missing. Diagnosis is typically by blood tests including a complete blood count, special hemoglobin tests, and genetic tests. Diagnosis may occur before birth through prenatal testing. Treatment depends on the type and severity. Treatment for those with more severe disease often includes regular blood transfusions, iron chel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
