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

Alpha thalassemia is the most common single gene mutation worldwide. In Thailand there exists 15-30% alpha-thalassemia carriers distributed throughout the country. DNA analysis by Southern blot hybridization reveals that the two major alpha-thalassemia alleles, alpha-thalassemia 1 and alpha-thalassemia 2 have different extents of alpha-globin gene deletion. In alpha-thalassemia 1, approximately 20 kb of DNA including the two linked alpha 1-and alpha 2-genes are removed and only the alpha-globin gene is intact. Total deletion of the alpha-globin gene cluster is rarely observed. In contrast, only one alpha-globin gene is deleted in alpha-thalassemia 2 of which two types have been detected, one involving a deletion of 4.2 kb of DNA (leftward type, -alpha 4.2) and another of 3.7 kb (rightward type, -alpha 3.7); the latter being more common than the former in Thailand. Compound heterozygosity for alpha-thalassemia 1 and alpha-thalassemia 2 results in HbH disease while homozygosity for alpha-thalassemia 1 leads to Hb Bart's hydrops fetalis, the most severe form of thalassemic disease. Three alpha-thalassemic hemoglobinopathies have been detected in Thailand, two of which produce a remarkable reduction in gene product. Upon interacting with alpha-thalassemia 1 gene they can lead to HbH disease. The most common in this group is Hb Constant Spring which arises from mutation of the termination codon in the alpha 2-gene resulting in an elongation of the alpha-globin chain.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:The molecular basis of alpha-thalassemia in Thailand. 129 97

Between 1970-1990, the Laboratory tested 38,391 specimens for hemoglobinopathies, of which 7,935 were positive. The major abnormalities detected were beta thalassemia trait (4,688), alpha thalassemia trait (1,248) and sickle cell trait (847). Clinically significant hemoglobinopathies detected were Hemoglobin H disease (100), sickle cell disease (67) and sickle cell Hemoglobin C disease (79). Hemoglobinopathies are therefore common in the Hamilton area as a reflection of the cultural diversity of area citizens. Of the 49 patients with thalassemia without documented iron deficiency, 8 (16%) received iron therapy for a variable period of time and 3 were investigated for gastrointestinal blood loss. Hemoglobin abnormalities cause or have the potential to cause clinical disease and they can, if not detected, result in unnecessary iron therapy or gastrointestinal investigation.
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PMID:The clinical significance of hemoglobinopathies in the Hamilton region: a twenty-year review. 145 12

A program for the detection of thalassemias and other hemoglobinopathies in high-risk populations is described. This program, based on two screening tests, was applied to the Hellenic Army recruits and was found to work well. Red cell one-point osmotic fragility was used for the detection of thalassemic samples and hemoglobin electrophoresis for screening of other hemoglobinopathies. Samples with decreased red cell osmotic fragility and/or abnormal electrophoretic pattern were submitted for further detailed investigation. Following this program, 64,814 recruits, representing 0.651% of the total Greek population and 9.917% of the 20-year-old Greek male population, were tested. beta-Thalassemia was found with an average incidence of 5.476% and alpha-Thalassemia with an incidence of 0.201%. Hemoglobinopathy Lepore was detected in 51 samples (0.079%) and hemoglobinopathy-S in 352 samples (0.543%).
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PMID:Diagnostic strategy for thalassemias and other hemoglobinopathies: a program applied to the Hellenic Army recruits. 162 Mar 78

The general background to child health in Saudi Arabia is reviewed. Information is provided on the social and demographic characteristics of the population, on common health indicators, on the health care system and its utilization, and on the general pattern of childhood morbidity and mortality. The unprecendented socioeconomic development has transformed the health care system. In 15 years the number of nurses have increased from 3261 to 29896, physicians from 1172 to 14335, primary health care centers from 591 to 1821, and hospital beds from 9036 to 30707. In spite of this progress, the disease pattern seems to resemble that of some developing countries with more limited resources. Parasitic diseases are still widespread, and sample surveys have indicated suboptimal nutrition of rural preschool children. Recent estimates on the infant mortality rate have ranged from 65 to 120 per 1000 live births. The preferred marriage partner is a close relative, and genetic diseases, such as hemoglobin disorders, are common in certain areas. Thus, the prevalence of alpha thalassemia is reported at 50 percent, and the sickle cell trait at 4.4-20 percent in sample surveys from the Eastern Province. The modest educational attainment of the mother, the heavy reliance on foreign manpower in all sectors, including the health sector, and the further development of the primary health care system are key issues today. It is emphasized that demographic and epidemiological information from Saudi Arabia is scarce and frequently uncertain, and that further studies are needed to identify the health needs of Saudi children.
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PMID:The ecological context of child health in Saudi Arabia. 322 47

Alpha-thalassemia is the most common cause of hydrops fetalis among Southeast Asians. With the recent influx of Southeast Asian refugees and the rapidly growing Filipino population this will become an increasingly important obstetric problem in the United States. Homozygous alpha-thalassemia, or Bart hemoglobinopathy, is invariably fatal to the fetus and produces significant maternal morbidity. Eighteen cases of homozygous alpha-thalassemia in one hospital are reviewed. This is the largest series reported in the United States. Recommendations are made for antenatal screening, diagnosis, and management of alpha-thalassemia.
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PMID:Hydrops fetalis secondary to Bart hemoglobinopathy. 394 25

Hematologic evaluations of 254 Southeast Asian refugee children from 163 families are reported. Hemoglobin E trait was common in Cambodians (19%) and Laotians (18%), but rare in Vietnamese (1%). beta-Thalassemia trait was most prevalent in Vietnamese (8%), and less common in Cambodians and Laotians (3%). alpha-Thalassemia was prevalent in all three groups. Hemoglobin concentrations and mean corpuscular volumes seen with hemoglobinopathies were compared with those of Southeast Asian children with normal hemoglobin. Both Hb AE and Hb EE were shown to be benign conditions resulting in microcytosis and mild, if any, anemia. In children with Hb AE, mean corpuscular volume ranged from 64 to 78 ft and Hb E from 27% to 34%. In those with Hb EE, microcytosis was more marked (50 to 63 ft). In 15 children with Hb EE, there was a delayed fall in fetal hemoglobin, which can cause diagnostic difficulties in infants.
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PMID:Anemia and hemoglobinopathies in Southeast Asian refugee children. 684 23

Three cases studies from the Regional Hemoglobinopathy Laboratory at St. Joseph's Hospital in Hamilton are presented. These cases demonstrate the diagnostic value of a comprehensive hemoglobinopathy screen, family studies, and appropriate clinical information in solving complex hemoglobinopathy problems. The first case is a 79-year-old woman found to have small amounts of an unknown hemoglobin migrating electrophoretically in the position of hemoglobin S. The second case describes a boy of Greek extraction with a thalassemic blood picture but otherwise normal hemoglobinopathy screen. The third case involves a 70-year-old man with a previously normal hemoglobinopathy screen who subsequently showed evidence of alpha thalassemia.
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PMID:Hemoglobinopathies: three illustrative case studies. 786 51

Hemoglobinopathies are the most common genetic disorders in Southeast Asia. alpha-Thalassemia is most often due to a alpha-globin gene deletion. Hb Constant Spring (CS) occurs from the mutation at the termination codon of the alpha-globin gene resulting in an elongated polypeptide; alpha(CS)-globin mRNA is also unstable and only small amounts of Hb CS are produced. Thus Hb CS has an alpha-thalassemia 2-like effect. beta-Thalassemia results from a variety of molecular mechanisms, most of which are single base substitutions or deletions or insertions of one to four nucleotides. Hemoglobin E occurs from a Glu --> Lys substitution at position 26 of the beta-globin chain. The abnormal gene also results in reduced amounts of beta E-mRNA and hence of beta E-globin chains. Therefore, Hb E has a mild beta + thalassemia phenotype. Homozygous beta-thalassemia and beta-thalassemia/Hb E are the major beta-thalassemic syndromes in Southeast Asia. In spite of seemingly identical genotypes, severity of beta-thalassemia/Hb E patients can vary greatly. Some may have a severe clinical disorder approaching that seen in homozygous beta-thalassemia. A number of genetic factors have been shown to determine the differences in severity of anemia in beta-thalassemia/Hb E, including co-inheritance of alpha-thalassemia determinants and co-inheritance of other determinants which elevate Hb F expression. A correlation between the extent of beta E-globin mRNA cryptic splicing and the severity of anemia in beta(zero)-thalassemia/Hb E patients has been observed. Complete characterization of mutations causing hemoglobinopathies will help to bolster the establishment of prenatal diagnosis of these genetic disorders in the region.
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PMID:Molecular mechanisms of thalassemia in southeast Asia. 862 13

Alpha thalassemia trait (alpha-thal-1) is a common cause of microcytosis in black and Asian populations. A small amount of hemoglobin Barts (2-8%) is transiently present in affected infants at birth and detectable in many newborn screening laboratories; it is a fast-moving hemoglobin on electrophoresis. In order to determine whether a report of a "fast hemoglobin variant" on newborn hemoglobinopathy screening is associated with a diagnosis of alpha thalassemia trait, hemoglobin concentration, red blood cell indices, and peripheral blood smear examination were performed on 18 infants referred for hematologic evaluation of a "fast hemoglobin variant" on newborn screening. All 18 infants with this diagnosis referred for consultation were black; ages ranged from 24 to 86 days (median 40 days). Six of 18 infants (33%) were mildly anemic for age and all 18 were microcytic. The prevalence of a "fast variant" among infants born at our institution is 2.5%. In that conditions other than alpha-thal-1 that cause microcytosis in early infancy are very uncommon, we conclude that all 18 of our infants with a fast hemoglobin on newborn screening likely have alpha-thal-1. The newborn screening result is thus a commonly and readily available laboratory report that specifically supports a diagnosis of alpha-thal-1, a diagnosis with significant clinical and genetic implications that is usually made only by exclusion.
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PMID:A fast hemoglobin variant on newborn screening is associated with alpha-thalassemia trait. 911 93

Twelve patients with anemias and their close relatives were examined: 8 adults (3 men and 5 women) and 4 children (3 boys and 1 girl). Six of them were Armenians, 1 woman was Russian, and the rest were of mixed origin: 3 Russian-Azerbaijan-Ukrainian, 1 child Russian-Ukrainian-African, and 1 woman Russian-Ukrainian. Hemoglobinopathies were detected in 10 subjects from 4 families (3 families from Donetsk and 1 from Moscow). Homozygotic beta-thalassemia major (Hb F 98.9%) was diagnosed in a 2-year-old Armenian girl from Donetsk. The girl lags behind in development and suffers from anemia with hepatosplenomegaly and jaundice. Heterozygotic beta-thalassemia minor with increased levels of Hb A2 and Hb F was diagnosed in her parents (Armenians from Azerbaijan). A 15-year-old Russian-Azerbaijan-Ukrainian boy from another family in Donetsk had beta-thalassemia with HbD (94%). The boy suffers from anemia with hepatosplenomegaly, jaundice, and chronic hepatitis. Heterozygotic beta-thalassemia with increased levels of Hb A2 and Hb F was revealed in proband's mother and brother; the father was not examined. alpha-Thalassemia is suspected in a 3-year-old boy from a Russian-Ukrainian-African family in Donetsk; he presented with a very small "fast" abnormal hemoglobin fraction. The boy suffers from anemia with splenomegaly and systolic murmur. Blurred form of thalassemia minor is diagnosed in the mother. The father, an African from Zaire, was not examined. Heterozygotic beta-thalassemia with increased Hb A2 level was revealed in a 20-year-old Armenian boy from Moscow. He presented with manifest splenomegaly, chronic gastritis, and mitral valve prolapse. His mother suffers from thalassemia minor, was anemic during pregnancy, and there are cases of anemia in the family. No hematologic disorders were found in the father. No hemoglobinopathies were detected in a 59-year-old Russian women from the town of Tver with very grave anemia; apparently, her condition was acquired, but not hereditary. Data on patients in the city of Donetsk are of special interest, for there are virtually no reports about hemoglobinopathies in the Ukraine.
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PMID:[Beta-thalassemia and Hb D in patients with anemia]. 957 28


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