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)

A 64-year-old man was admitted due to ascites. Laboratory data showed hemoglobin 6.7 g/dl, mean corpuscular volume 82 fl, and ferritin 2,360 ng/ml. Liver biopsy showed hemochromatosis. The diagnosis of beta-thalassemia was suggested by a decreased ratio of beta/alpha-globin synthesis in vitro (0.26). Cloning of the beta-globin gene showed A-to-G mutation in the first base of the ATA box. He was confirmed to be homozygous for this specific allele by beta-gene complex analysis and analysis of Southern blot hybridization of the alpha- and beta-globin genes. His two sons were confirmed to be heterozygous for this allele.
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PMID:Beta(+)-thalassemia with hemochromatosis. 136 99

Sequence analyses of amplified DNA from a Yugoslavian patient with Hb Lepore-beta-thalassemia and from his father with a simple beta-thalassemia trait have revealed a T----A mutation within the ATA box at a position 30 base pairs upstream from the Cap site. The nucleotide substitution was confirmed through dot-blot analysis of amplified DNA with specific 32P-labeled synthetic oligonucleotide probes. The patient had a clinically severe condition; his Hb Lepore-beta-thalassemia was of the beta + type, as about 8-10% of the non-alpha chain was normal beta A. The same T----A mutation at nucleotide -30 was present on both chromosomes of a young Turkish patient who suffered from a thalassemia intermedia with a low level of Hb F (13.1%) and a relatively high beta A chain synthesis. These data are similar to those obtained for other types of beta +-thalassemia caused by comparable substitutions at positions 31, 29, and 28 base pairs upstream from the Cap site of the beta-globin gene.
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PMID:Beta-thalassemia due to a T----A mutation within the ATA box. 338 1

In summary, the beta-thalassemias are due to defects in or around the structural beta-globin gene. In some Indian patients, there is deletion of sequence at the 3' end of the beta-globin gene. Most commonly, single nucleotide mutations cause beta(+)- and beta(0) -thalassemia. More than 30 such mutations have been identified. Defects in the promoter region 5' to the gene as far 5' as -87 and closer to the gene at -27 and -28 in the ATA sequence can cause beta (+)-thalassemia. Single nucleotide changes in coding regions leading to termination or nonsense codons commonly cause beta (0)-thalassemia. In addition, beta(0)-thalassemia can be due to single nucleotide changes in the invariant GT at the 5' splice junction in IVS 1 and 2 and in the AG at the 3' end of IVS 2. Additionally, single nucleotide mutations can occur within IVS that result in both beta(+)- and beta(0)-thalassemia. New splice sites are usually the result of these single nucleotide mutations, and they lead to new, abnormal splicing patterns. In some instances, beta (+)-thalassemia results when a new splice signal created within IVS is still associated with some continued normal splicing as well as with abnormal splicing. The abnormal splicing leads to abnormal mRNA, while the normal splicing leads to some normal mRNA and the beta (+)-pheno-single In other cases, such as with the defect as position 705 of IVS 2, the single nucleotide change within the IVS allows only abnormal mRNA splicing, and it results in beta (0)-thalassemia.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Beta-thalassemia syndromes. 368 46

DNA sequence analysis of a cloned beta-globin gene from a Chinese patient with beta-thalassemia revealed a single nucleotide substitution (A leads to G) within the ATA box homology and 28 base pairs upstream from the cap site. The patient was homozygous for this particular allele based on restriction mapping at nine different polymorphic sites in the beta-globin gene cluster. Upon transient expression in HeLa cells this gene directed the production of 3-5-fold less beta-globin mRNA than the normal beta-gene. In RNA isolated from the patient's erythroid cells beta-RNA was 10-fold less abundant relative to alpha-RNA than normal, indicating close approximation of the heterologous cell expression results and the in vivo state. These findings support the validity of such transient expression assays for analysis of phenotypes associated with naturally occurring mutant genes and establish the functional significance of nucleotide substitutions at position -28 for human beta-globin gene transcription.
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PMID:ATA box transcription mutation in beta-thalassemia. 630 58

Thalassaemia is the most common genetic disease and is a public health problem of Thailand. Prevention and control of beta-thalassaemia diseases need accurate diagnosis of carriers and proper genetic counselling. Prenatal diagnosis is needed to prevent birth of the thalassaemic offspring in the couple at risk. This can be performed in the first trimester of pregnancy by DNA analysis using the polymerase chain reaction (PCR). Since there are more than 20 mutations causing beta-thalassaemia in Thailand, the point mutation detection by reverse dot-blot allele-specific oligonucleotide (ASO) hybridization was developed using two sets of ASO probes. The first battery of ASO probes has been designed to detect 10 common beta-globin gene mutations including codon 26, G->A (Hb E): codons 41/42, -TCTT; codon 17, A->T; IVS 2 nt 654, C->T; IVS 1 nt 1, G->T; IVS 1 nt 5. G->C; codon 19, A->G (Hb Malay); codon 35, C->A; codons 71/72, +A and -28 ATA, A->G. The second set of ASO probes detect 14 uncommon beta-thalassaemia mutations. We applied this reverse dot-blot hybridization technique to perform prenatal diagnosis in 105 pregnancies at risk of having severe beta-thalassaemia diseases. 36 fetuses (34 per cent) were found to be affected with homozygous beta-thalassaemia or beta-thalassaemia/Hb E disease in which one was twin pregnancy. The others included 31 fetuses with heterozygous beta-thalassaemia, 22 heterozygous Hb E, 1 homozygous Hb E and 16 normal fetuses. The common set of ASO probes detected about 95 per cent of cases which suggests that prenatal diagnosis for beta-thalassaemia disease can be easily carried out by this approach.
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PMID:Prenatal diagnosis of beta-thalassaemia by reverse dot-blot hybridization. 1036 May 11

We have characterized a new abnormal hemoglobin (Hb) at position 32 of the alpha-globin chain. The proband, a 38-year-old woman of Surinamese Black ancestry, was referred to the Academic Hospital in Amsterdam, The Netherlands, after 3 years of Prednisone treatment in Surinam. Kidney failure was diagnosed at the Nephrology Department, Free University Medical Center, Amsterdam, The Netherlands; the cortisone treatment was interrupted and dialysis was started. At this stage, a microcytic hypochromic anemia was observed with high reticulocyte (40%) and ferritin (500 microg/L) levels, and hemoglobinopathy was suspected. No abnormal bands were visible on alkaline electrophoresis and high performance liquid chromatography (HPLC). The Hb A2 level was normal (2.7%) and the erythrocyte count was low (3.59 x 10(12)/L) with a normal haptoglobin level (68 mg/100 mL). None of the common alpha-thalassemia (thal) deletion defects were present. The beta-globin gene sequence was normal but the alpha2-globin gene sequence revealed an ATG-->ATA transition at codon 32, changing the methionine into an isoleucine residue. The mutation, called Hb Amsterdam, was observed in the mother of the proband, who was also heterozygous for the--alpha3.7-thal deletion and affected by a moderate microcytic hypochromic anemia. Both Hb Amsterdam and the--alpha(-3.7) allele were found in association with a new polymorphism, IVS-I-39 (C-->T), previously observed in our laboratory in seven patients of African origin, on both the alpha1 and alpha2 genes. In addition, Hb Amsterdam was also associated with the common African alpha2 polymorphism (G-->CTCGGCCC at position 7238 and T-->G at position 7174). Hb Amsterdam is the first mutation ever described at codon alpha32, a position involved in alpha1/beta1 interaction. The possibility of a contribution of this mutation to the nephropatic state of the proband is discussed.
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PMID:Hb Amsterdam [alpha32(B13)Met--Ile (alpha2)]: a new unstable variant associated with an alpha-thalassemia phenotype and a new African polymorphism. 1637 Apr 85

Deferiprone (L1), has previously been reported to be associated with immunological abnormalities in iron loaded thalassemia patients. However, other factors may also have similar effects such as the level of iron overload, chronic immuno-stimulation due to transfusions, splenectomy and deferoxamine (DFO). During chelation therapy with DFO, several complications have been reported, which were due to pharmacological activity and high dose toxicity with regard to both acoustic and visual effects, as well as peripheral nerve disorders that were measured by nerve conduction velocities. The immune and neural status of 44 beta-thalassemic patients, aged 10-30 years (mean 19.4 +/- 4.9), receiving L1 as a monotherapy (n = 21), or in combination with DFO (n = 23), has been followed for 2 years by monitoring the level of immunoglobulins (IgG, IgM, IgA), the level of T and B lymphocytes (CD4/CD8), the auto antibodies: anti nuclear (ANA), anti-double-stranded (anti-ds DNA), anti reticulin (anti-R1), anti-extra nuclear (anti-ENA), anti histone (anti-AHA), anti liver-kidney-muscle (anti-LKM), anti-smooth muscle (anti-SMA), anti-thyroid (anti-ATA), anti-mitochondrial (anti-AMA) antibodies and the C-reactive protein. The percentage of patients with disorders of the immune and nervous system concerned very few cases. None of our patients with pathological findings in their immunological or neurophysiological examinations presented any signs or symptoms of involvement of the immune or nervous system. Further advantages have been identified for the oral use of L1 and its combination with DFO, including synergistic efficacy and lower dosing with limited toxicity.
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PMID:Immune and neural status of thalassemic patients receiving deferiprone or combined deferiprone and deferoxamine chelation treatment. 1827 81

We report the characterization of five novel delta-globin gene mutations detected during routine screening for thalassemia. Three missense mutations were identified, resulting in the following delta chain hemoglobin (Hb) variants: Hb A(2)-Acacias [delta4 (ACT>AGT), Thr-->Ser, HBD c.14C>G], Hb A(2)-Toronto [delta74 (GGC>GAC), Gly-->Asp, HBD c.224G>A], and Hb A(2)-Calgary [delta99 (GAT>GGT), Asp-->Gly, HBD c.299A>G]. Two other mutations most likely result in delta(0)-thalassemia (delta(0)-thal). One mutation altered the translation initiation codon from ATG to ATA (HBD c.3G>A), and another changed the canonical splice donor sequence of IVS-II from GT to AT (HBD C.315+1G>A).
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PMID:Characterization of three novel delta chain hemoglobin variants and two delta-thalassemia alleles. 2064 35