Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0039730 (thalassemia)
 10,305 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The global health impact of malaria is enormous, with an estimated 300-500 million clinical cases and 1 million annual deaths. In humans, initial susceptibility to infection with Plasmodium species, disease severity and ultimate outcome of malaria (self-healing or lethal) are under complex genetic control. Alleles associated with sickle cell anemia, beta-thalassemia and deficiency in glucose-6-phosphate dehydrogenase have a protective effect against malaria and may have been retained by positive selection in areas of endemic malaria. Likewise, genetic variations in erythrocyte antigens and levels of host cytokines affect type and severity of disease. A mouse model of infection with Plasmodium chabaudi was used to study the genetic component of malaria susceptibility. Segregation analyses in informative F2 crosses derived from resistant C57BL/6J and susceptible A/J, C3H and SJL strains using extent of blood stage replication of the parasite and survival as traits mapped three P. chabaudi resistance (Char) loci on chromosomes 9 (Char1), 8 (Char2) and 17 (Char3, MHC-linked). Recombinant congenic strains AcB55 and AcB61 are unusually resistant to malaria despite carrying susceptibility alleles at Char1 and Char2. Malaria resistance in AcB55 and AcB61 is associated with splenomegaly and constitutive reticulocytosis, is inherited in an autosomal recessive fashion and is controlled by a locus on chromosome 3 (Char4). Sequencing of candidate genes from the Char4 region identified a loss-of-function mutation (269T-->A, resulting in the amino acid substitution I90N) in the pyruvate kinase gene (Pklr) that underlies the malaria resistance in AcB55 and AcB61. These results suggest that pyruvate kinase deficiency may similarly protect humans against malaria.
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PMID:Pyruvate kinase deficiency in mice protects against malaria. 1459 40

We assessed the prevalence of three common hereditary blood disorders (sickle-cell and beta-thalassaemia traits and glucose 6-phosphate dehydrogenase deficiency) among the Omani population. We interviewed a representative sample of 6103 Omani households and blood samples from 6342 children aged 0-5 years were collected. About 27% of Omani males had inherited glucose-6-phosphate dehydrogenase deficiency (compared with 11% of females) while countrywide prevalence rates for the sickle-cell and beta-thalassaemia traits were estimated to be 5.8% and 2.2% respectively and showed no significant gender differences. There was a significant association between all three disorders and region of the country.
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PMID:A community-based study of common hereditary blood disorders in Oman. 1533 42

Basra, southern Iraq, was mapped for haemoglobinopathies and glucose-6-phosphate dehydrogenase (G6PD) deficiency. Of 1064 couples aged 14-60 years recruited from the Public Health Laboratory, 49 had beta-thalassaemia trait, 69 had sickle-cell trait, 2 had haemoglobin D trait, 2 had haemoglobin C trait and 1 had high persistent fetal haemoglobin. Carriers of major beta-globin disorders comprised 11.48%. G6PD deficiency was detected in 133 individuals (12.5%). Only 10 couples (0.94%) were at risk of having children affected with either sickle-cell disease or beta-thalassaemia major. These defects constitute a real health problem and necessitate a management plan and public health education for early diagnosis and therapy.
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PMID:Frequency of haemoglobinopathies and glucose-6-phosphate dehydrogenase deficiency in Basra. 1556 32

In Bahrain and neighbouring countries inherited disorders of haemoglobin, i.e. sickle-cell disease, thalassaemias and glucose-6-phosphate dehydrogenase (G6PD) deficiency, are common. As part of the National Student Screening Project to determine the prevalence of genetic blood disorders and raise awareness among young Bahrainis, we screened 11th-grade students from 38 schools (5685 students), organized lectures and distributed information about these disorders. Haemoglobin electrophoresis, high performance liquid chromatography, blood grouping and G6PD deficiency testing were performed. Prevalences were: 1.2% sickle-cell disease; 13.8% sickle-cell trait; 0.09% beta-thalassaemia; 2.9% beta-thalassaemia trait; 23.2% G6PD deficiency; 1.9% G6PD deficiency carrier. Health education, carrier screening and premarital counselling remain the best ways to reduce disease incidence with potentially significant financial savings and social and health benefits.
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PMID:Student screening for inherited blood disorders in Bahrain. 1575 27

Gene analysis in Japanese patients with congenital hemolytic anemia due to red cell membrane disorders, thalassemias, unstable hemoglobinopathies and red cell enzymopathies were summarized. In hereditary spherocytosis, twenty-four mutations of band 3, five mutations of protein 4.2 and twenty mutations of ankyrin have been identified. In beta thalassemia, fourty-seven mutations of beta globin have been found, and ten mutations among them comprise 80% of beta thalassemia patients in Japan. Most common alpha0 and alpha+ thalassemia are--SEA and--alpha3.7, respectively. Fourty glucose-6-phosphate dehydrogenase mutations and twenty-three pyruvate kinase mutations have been identified, allowing a better understanding of the structure-function relationships of these enzymes.
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PMID:[Congenital hemolytic anemia]. 1577 39

Tumour necrosis factor-alpha (TNF-alpha) is one of the key cytokines that influence the pathology of microbial infections. The genetic susceptibility to severe forms of falciparum malaria is differentially associated with TNF-alpha promoter gene polymorphisms (TNFP alleles). In a previous study, we identified a TNFP-allele characterized by a C to T transition at position -857 (TNFP-D allele) as a marker for susceptibility to cerebral malaria in Myanmar. The frequencies of TNFP alleles on six islands of Vanuatu, Melanesia (South-west Pacific) were estimated to investigate whether malaria selection pressure on this susceptibility marker has influenced its prevalence. Within the archipelago of Vanuatu there is a decreasing cline of parasite incidence from North to South. Of the four alleles of the TNFP gene detected in Vanuatu, the TNFP-D allele frequencies were inversely correlated with the parasite incidence of islands; TNFP-D varied from 0.55 on the island with the lowest parasite incidence to 0.26 on the island with the highest parasite incidence (r = -0.855, P = 0.03). We also observed a significant correlation between the frequencies of alpha-thalassaemia alleles, thought to protect against malaria and parasite incidence in the same populations. These data are consistent with a previously reported correspondence between the frequencies of glucose 6-phosphate dehydrogenase (G6PD) deficiency and parasite incidences on the islands of Vanuatu (Kaneko et al. 1998) and indicate that the degree of malaria endemicity has influenced the allele frequencies of at least three loci that confer both susceptibility (TNFP-D) and protection (alpha-thalassaemias and G6PD deficiency).
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PMID:Associations between frequencies of a susceptible TNF-alpha promoter allele and protective alpha-thalassaemias and malaria parasite incidence in Vanuatu. 1594 17

Samples from 916 members of various ethnic groups from malaria-endemic southern Shan State, Myanmar, were analyzed for 3-thalassemia (3-thal), 3-thalassemia (3-thal), abnormal hemoglobin variants, and glucose-6-phosphate dehydrogenase (G6PD) deficiency. Of these subjects, 530 (57.9%) were found to have at least one of these red cell genetic disorders. The overall frequencies for the various red cell genetic disorders were as follows: 3-thal, 37.5% (343/916); hemoglobin E (Hb-E), 20.3% (186/916); G6PD-Mahidol, 17.5% (160/916); and 3-thal, 0.3% (3/916). The frequencies of combined disorders were 6.9% (63/ 916) for 3-thal/Hb-E, 5.7% (52/916) for 3-thal/G6PD-Mahidol, 2.8% (26/916) for Hb-E/G6PD-Mahidol, 1.1% (10/916) for 3-thal/Hb-E/G6PD-Mahidol, and 0.1% (1/916) for 3-thal/3-thal/G6PD-Mahidol. Of the various ethnic and non-ethnic groups, the Bamar population showed the highest frequencies of 3-thal (56.9%, 177/311), Hb-E (28.3%, 88/311), and G6PD-Mahidol (21.2%, 66/311) (all duplicated and triplicated cases were included). In addition, 2 new mutations, an 3 gene triplication (/333(anti3.7); 0.2%, 2/916) and Hb-Neapolis (0.1%, 1/916), were detected. Our results showed that race was the dominant factor affecting the frequencies of red cell genetic disorders in malaria-endemic areas of Myanmar.
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PMID:High incidence of 3-thalassemia, hemoglobin E, and glucose-6-phosphate dehydrogenase deficiency in populations of malaria-endemic southern Shan State, Myanmar. 1614 42

The purposes of this study were to evaluate the reliability of the previously described diagnostic criteria for Southeast Asian ovalocytosis (SAO) in adults in the diagnosis of SAO in newborns and to describe the role of SAO in newborn infants presenting with pallor and jaundice. The inclusion criteria in this retrospective descriptive study were that the patient be a newborn with pallor or jaundice and with ovalocytes in the peripheral blood smear (PBS). The exclusion criteria were newborn status with other causes of neonatal hemolysis or anemia. Controls were age-matched newborn infants who did not have SAO or other causes of neonatal anemia or hemolysis. Hematological data were assessed with a hematology analyzer. DNA analysis for SAO band 3 was done by polymerase chain reaction. Among 107 newborn infants with SAO, 30 infants were excluded from the study. The exclusions were premature infants, an infant with congenital syphilis, low-birth-weight infants, infants with ABO blood group incompatibility, infants with 3-thalassemia, infants with hemoglobin E heterozygote or homozygotes, glucose-6-phosphate dehydrogenase-deficient infants, and infants with fetomaternal hemorrhage. The DNA analysis for SAO band 3 was done in 56 newborns, and 54 had positive results for SAO band 3 gene deletion. Approximately one half of the 54 newborn infants with SAO had hyperbilirubinemia, and 3 had severe hyperbilirubinemia. The mean hemoglobin concentration, packed cell volume, and red blood cell (RBC) count in the infants with SAO in the first week of life were significantly lower than those in control infants. The mean absolute number of reticulocytes, mean corpuscular hemoglobin, and red cell volume distribution width in infants with SAO band 3 in the first week of life were significantly higher than those in control infants. The neonatal diagnosis of SAO can be made by examination of RBC morphology in the PBS with the presence of stomatocytes, theta cells, and > or = 25% ovalocytes. SAO plays a role in anemia and hyperbilirubinemia in newborn infants.
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PMID:Neonatal anemia associated with Southeast Asian ovalocytosis. 1620 91

Tribal communities in India constitute the largest tribal population in the world. There are about 635 biological isolates (tribes and subtribes), which constituted 8.08% (about 84.3 million) of the total population of India as per the 2001 census. Out of 635 scheduled tribes (aborigines), 62 live in the state of Orissa alone forming about 10.8% of the tribal population of India. Orissa state occupies an important place, being the 3rd in rank for the highest concentration of tribal population in the country. In India, tribal communities are highly vulnerable to hereditary diseases and have a high degree of malnutrition, morbidity and mortality. The sickle cell haemoglobinopathy and glucose-6-phosphate dehydrogenase (G6PD) enzyme deficiency are important genetic and public health problems in Central-Eastern part of India. In order to map out these genetic disorders among the tribal people, a cross-section of 15 major tribal communities from different parts of Orissa was randomly screened for haemoglobin variants and G6PD deficiency. The high frequency of sickle cell haemoglobinopathy (0-22.4%) and G6PD deficiency (4.3-17.4%), with beta-thalassemia trait (0-8.5%) taking almost an intermediate position, was observed. For G6PD deficiency, hemizygous males as well as female heterozygotes and female homozygotes were detected. Twelve cases showed compound heterozygosity for sickle cell haemoglobinopathy and G6PD deficiency. There seems to be a trend towards an inverse relationship between the sickle cell allele and G6PD deficiency, and sickle cell and beta-thalassemia allele in a cross-section of malaria endemic (Plasmodium falciparum) tribal communities in Orissa. When the frequency of sickle cell allele decreases in a cross-section of malaria endemic tribal population, the frequency of G6PD enzyme deficiency and beta-thalassemia allele increases and vice versa. Natural selection had played a major role in favour of sickle cell, beta-thalassemia and G6PD mutation alleles so that they had probably evolved as a protective mechanism against the lethal effects of malaria in this part of the country. However, the calculated values of 0.074, 0.218 and 0.337, respectively, of Pearson's correlation co-efficient (r), showed no correlation between sickle cell disorders and G6PD deficiency, sickle cell disorders and beta-thalassemia, and G6PD deficiency and beta-thalassemia.
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PMID:Do tribal communities show an inverse relationship between sickle cell disorders and glucose-6-phosphate dehydrogenase deficiency in malaria endemic areas of Central-Eastern India? 1660 61

This study was conducted on a selected population of Al-Qatif in Eastern Saudi Arabia to determine the gene frequencies of glucose-6-phosphate dehydrogenase (G-6-PD) deficiency and sickle cell (HbS) genes and to study the extent of interaction between the two genes. A total of 960 blood samples collected from Saudi males (515) and females (445) attending the outpatient clinics and hospitals for minor illnesses were subjected to electrophoresis for separation of hemoglobin types and G-6-PD phenotyping and for spectrophotometric determination of G-6-PD activity. The prevalence of HbS heterozygotes was 25.9%, Hb S/b_-thalassemia was 1.563% and HbS homozygotes was 2.917%. The overall gene frequency of HbS was 0.1666. Severe glucose-6-phosphate dehydrogenase deficiency was encountered in a large percentage of the population with a frequency of 0.392 for G-6-PD Mediterranean and 0.0058 for G-6-PD-A- in the male population and 0.2020 and 0.0112 for G-6-PD Mediterranean and G-6-PD-A- in the female population respectively. Partial deficiency was encountered at a frequency of 0.0272 and 0.0697 in the male and female populations respectively. G-6-PD deficiency caused by G-6-PD Mediterranean occurred at a higher frequency in individuals with normal hemoglobin (Hb AA) (0.414 and 0.217 in males and females respectively) compared to the HbS heterozygotes (0.338 and 0.168 in males and females respectively) and HbS homozygotes and HbS bo-thalassemia cases (0.3125 and 0.1852 in males and females respectively). Compared to all areas of Saudi Arabia, Al-Qatif had the highest gene frequencies for HbS and G-6-PD deficiency genes.
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PMID:The frequency of glucose-6-phosphate dehydrogenase phenotypes and sickle cell genes in Al-Qatif oasis. 1758 56


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