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)

Thalassemia is a common genetic disorder among the South Chinese. To see if thalassemia would adversely affect the erythrocyte response to recombinant human erythropoietin (rHuEPO, Epogen) in dialysis patients, the response to rHuEPO in 4 dialysis patients with thalassemic traits (thal-t) was compared with that of 4 control patients who were matched for age, sex, mode of dialysis and baseline hemoglobin levels over a 6-month period. Patients with thal-t showed a reduced erythrocyte response to rHuEPO compared to control dialysis patients as reflected by a reduced reticulocyte index, a slower rise in hemoglobin or hematocrit levels, requirement of a higher cumulated dose of rHuEPO to achieve a target hemoglobin of 10 g/dl and a higher maintenance dose of rHuEPO. A dialysis patient with hemoglobin H disease (HbHD) was also studied. He failed to respond to rHuEPO despite that the dose was increased to 250 U/kg/week. In contrast, his matched control dialysis patient, despite a lower baseline hemoglobin level (6.1 versus 8.8 g/dl), was able to reach a target hemoglobin level of 10 g/dl by 6 weeks and could be maintained at this level with 50 U/kg/week. The patient with HbHD had splenomegaly and a higher baseline serum erythropoietin level, reticulocyte count, serum bilirubin, serum ferritin and serum iron saturation than control patients and patients with thal-t. It was concluded that thal-t reduces the erythrocyte response to rHuEPO in dialysis patients and that in the presence of active hemolysis and enhanced endogenous erythropoietin secretion, dialysis patients with HbHD are resistant to treatment with rHuEPO.
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PMID:Influence of thalassemia on the response to recombinant human erythropoietin in dialysis patients. 834 81

Sickle cell anaemia is a hereditary disorder commonly seen in the black population, due to a point mutation in the beta globin gene. The sickle mutation is responsible for an increased rigidity and adherence of the red blood cell leading to haemolytic anaemia and vaso-occlusive episodes. Symptoms include dactylitis, painful crisis, splenic sequestration and the development of multi-organ damage and failure. The progressive loss of splenic function increases the risk of infections. The morbidity and mortality can be reduced by the maintenance of an adequate nutrition, the prevention of infection and the treatment of complications. In some patients severely affected, a chronic transfusion program has to be instigated to maintain a level of haemoglobin S below 50%. New therapeutic strategies include the use of hydroxyurea and maybe, in the future, butyrates to increase the level of foetal haemoglobin. Further studies are needed to evaluate the benefits of such therapies. Bone marrow transplantation represents an attractive therapeutic tool and its role in other haemoglobinopathies like thalassaemia is now well demonstrated. As far as sickle anaemia is concerned, the first report concerned a child with acute myeloblastic leukaemia. The patient is now cured of both the sickle cell anaemia and the leukemia. Since April 1986, 21 patients underwent an allogeneic bone marrow transplantation for sickle cell anaemia in our department. 20 patients became asymptomatic and have an electrophoretic pattern of the haemoglobin similar to that of the donor. One patient died of bone marrow transplantation related complications.
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PMID:Bone marrow transplantation in sickle cell anaemia. 846 26

The -175 (T-->C) G gamma hereditary persistence of fetal haemoglobin is a very rare promoter mutation occurring in Caucasians as well as in African-Americans. Heterozygotes for this non-deletional HPFH show 20% HbF, mostly of G gamma type. We describe here a healthy Sardinian man who coinherited -175 (T-->C) G gamma HPFH with the beta-thalassaemia codon 39 nonsense mutation in trans; he showed 64% HbF, 100% of G gamma type. Although the beta-globin haplotype pattern (II/II) was indicative of the presence of the A gamma T allele on both chromosomes, the A gamma T expression was undetectable by HPLC even in red cell populations separated by age. The proband was, moreover, homozygous for the -4 bp deletion at position -225 to -222 of A gamma promoter which has recently been associated with decreased A gamma T globin expression. These findings suggest that this maximal overexpression of G gamma-globin probably reflects intensified stimulation of the mutated G gamma promoter in this hitherto undescribed genetic condition.
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PMID:Maximal gamma-globin expression in the compound heterozygous state for -175G gamma HPFH and beta degree 39 nonsense thalassaemia: a case study. 922 87

Beta-thalassaemia major is a serious genetic disorder, which results in a considerable increase in both acute and chronic morbidity, and mortality. Although beta-thalassaemia major is a rare disease affecting approximately 600 people in the UK, treatment is intensive and predictions of the costs incurred may aid health care planning. In this report, the cost to the health service of providing treatment services for beta-thalassaemia major patients, over the course of a lifetime, is calculated in order to assist resource allocation decisions. A cost model was developed, incorporating data from disparate sources. The undiscounted lifetime cost of treating a beta-thalassaemia major patient was estimated to be pound 803,002, although when the costs were discounted at a rate of 6%, the lifetime cost was reduced to pound 219,068. Within sensitivity analyses, the discounted cost ranged from approximately pound 188,000 to pound 226,000. This report may act as a guide to those involved in the planning of health care provision with regard to the resources required to treat beta-thalassaemia major patients. Such information may also be incorporated into the decision-making process for the provision of antenatal screening programmes for beta-thalassaemia major.
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PMID:Lifetime treatment costs of beta-thalassaemia major. 1067 89

Thalassemia is a prevalent hereditary disorder characterized by impaired synthesis of globin chains. It has been suggested that the high frequency of thalassemia might reflect heterozygote advantage due to reduced susceptibility to malaria. In Nepal, malaria has often occurred in places below the altitude of 1,200m. We carried out a microepidemiological study on thalassemia in two neighboring populations in Nepal, the Danuwar and the Tamang. Settlements of the Danuwar are located below the limit of the malarial zone (1,200m in altitude), whereas those of the Tamang are found in malaria-free uplands. Three heterozygotes for hemoglobin E (HbE) were observed in the Danuwars. We detected one type (-alpha3.71) of alpha+-thalassemia that involves a deletion of 3.7kb, leading to a loss of one of two alpha-globin genes, in the Danuwars, at a high gene frequency of 63%, while the gene frequency in the Tamangs was only 5%. Analysis of the alpha-globin gene cluster revealed that four different haplotypes were associated with the type of alpha+-thalassemia in the Danuwars. Nucleotide sequences of the D-loop region in the mitochondrial DNA of the two populations indicated a similar nucleotide diversity in each population. The fixation index, FST, representing the degree of genetic differentiation estimated from mitochondrial DNA diversities (FST, 0.05), was smaller than that obtained from the gene frequencies of alpha-thalassemia (FST, 0.55). If we assume neutral molecular evolution in the D-loop region of mitochondrial DNA, these results suggest that the high frequency of alpha+-thalassemia may be due to biological adaptation to the malarial environment rather than to events such as a bottleneck.
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PMID:Molecular analysis of alpha-thalassemia in Nepal: correlation with malaria endemicity. 1080 36

A service for prenatal diagnosis of beta-thalassaemia was introduced in Pakistan in May 1994. Two renowned Islamic scholars, consulted before the service was introduced, ruled that a pregnancy can be terminated if the fetus is affected by a serious genetic disorder, and if termination is before 120 days (17 weeks) of gestation. During the first 3(1/2) years of the service 300 couples requested the test. Almost all the couples had been informed by their treating doctors. Most diagnoses were made between 10 and 16 weeks of gestation, and only 15 (5%) were reached after the 16th week. DNA analysis was by the amplification refractory mutation system (ARMS). A multiplex ARMS was developed in which three primer combinations identified the mutations in 91.5% of the couples. In 13 couples (4. 3%) linkage analysis was required for the fetal diagnosis. In 47/53 (88.7%) women carrying an affected fetus the pregnancy was terminated. In six cases it was declined principally on religious grounds. Postnatal confirmation of the prenatal diagnosis was possible in 117 unaffected children. One year after the start of the service, interviews with 141 couples with an affected child showed that 72% knew of the availability of prenatal diagnosis. Thirty-two of the informed couples had had a pregnancy, but only 18 (56%) used prenatal diagnosis. The main reasons for non-utilization of prenatal diagnosis were the cost of the test and fear of undergoing the test, though some gave no clear explanation. This study demonstrates that prenatal diagnosis is feasible and acceptable in a Muslim country such as Pakistan.
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PMID:Prenatal diagnosis of beta-thalassaemia in Pakistan: experience in a Muslim country. 1082 Apr 4

X-linked sideroblastic anemia (XLSA) is caused by mutations in the erythroid-specific 5-aminolevulinic acid synthase (ALAS2) gene. An elderly woman who presented with an acquired sideroblastic anemia is studied. Molecular analysis revealed that she was heterozygous for a missense mutation in the ALAS2 gene, but she expressed only the mutated gene in reticulocytes. Her 2 daughters and a granddaughter were heterozygous for this mutation, had normal hemoglobin levels, and expressed the normal ALAS2 gene in reticulocytes. A grandson with a previous diagnosis of thalassemia intermedia was found to be hemizygous for the ALAS2 mutation. Treatment with pyridoxine completely corrected the anemia both in the proband and her grandson. All women who were analyzed in this family showed skewed X-chromosome inactivation in leukocytes, which indicated a hereditary condition associated with unbalanced lyonization. Because the preferentially active X chromosome carried the mutant ALAS2 allele, acquired skewing in the elderly likely worsened the genetic condition and abolished the normal ALAS2 allele expression in the proband. (Blood. 2000;96:4363-4365)
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PMID:Familial-skewed X-chromosome inactivation as a predisposing factor for late-onset X-linked sideroblastic anemia in carrier females. 1140 13

Genetic counselling is the process by which an individual or a family obtains information about a genetic condition that may affect them, so that they can take the appropriate decisions about marriage, reproduction and health management. Islamic teaching encourages counselling and stresses that the counsellor should be considerate, compassionate and should keep the secrets of the person or family involved. He/she should not impose his/her views on the clients. Some Arab countries encourage premarital medical examination to detect carriers of common hereditary diseases such as thalassaemia. However, this is still controversial, as it infringes the human rights of individuals. Reproductive options open to carriers of hereditary diseases are outlined in this paper, such as prenatal diagnosis, adoption, donation of a sperm, ova or preembryo and preimplantation diagnosis, and their acceptability within Islam is discussed.
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PMID:Counselling about genetic disease: an Islamic perspective. 1192

The year 2000 saw the first successful treatment of a genetic disorder by gene therapy. Pediatric patients with X-linked severe combined immunodeficiency disorder (SCID-X1) received autologous CD34+ hematopoietic cells following ex vivo gene transfer using a retroviral vector, with subsequent demonstration of improved immune responses. A number of preclinical and clinical studies have been conducted with the aim of developing gene therapy for hemophilia, Fanconi anemia, sickle cell disease, beta-thalassemia, chronic granulomatous disease, and other inherited hematological disorders. The greatest advances in novel approaches toward treatment of hematological disorders have been made in hemophilia, with 3 current phase I clinical trials ongoing. Two trials are investigating the safety and feasibility of utilizing either an ex vivo, non-viral gene transfer technique or an intravenous infusion of a retroviral vector to treat adults with severe hemophilia A (factor VIII deficiency). The third study involves intramuscular administration of an adeno-associated viral (AAV) vector for expression of factor IX in adult patients with hemophilia B. Results from this study and from preclinical studies preceding the trial demonstrate that it is possible to safely administer high doses of a viral vector in vivo.
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PMID:Gene therapy for hereditary hematological disorders. 1217 74

Genetics is an important area of focus for the preconception visit (Table 4). Folic acid should be recommended for all women. The genetic and pregnancy history should be evaluated for clues to a genetic disorder. Preconception screening and counseling are available for many diseases that are indicated in the family history. Screening may be offered for sickle cell anemia, thalassemia, Tay Sachs disease, and cystic fibrosis in the appropriate population groups. Older couples should be counseled about their increased risks for having complications during pregnancy and for having children with genetic disorders.
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PMID:Genetics issues in preconception health care. 1241 84


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