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

We describe a new deletional form of gamma delta beta-thalassemia segregating in two generations of a family of Irish descent. Affected family members present with a beta-thalassemia minor phenotype, normal Hb A2 and Hb F levels. Genomic blotting analyses on DNA from affected family members show heterozygosity for a large deletion beginning at least 15 kb upstream of the 5' endpoint of the gamma delta beta-thalassemia-1 deletion, extending through the entire beta-like globin gene cluster, and continuing for at least 10 kb beyond the 3' endpoint of the deletion associated with the Spanish form of delta beta 0-thalassemia. This deletion is among the largest described so far, and removes at least 205 kb encompassing the entire beta-like globin gene cluster on chromosome 11.
 ...
PMID:A greater than 200 kb deletion removing the entire beta-like globin gene cluster in a family of Irish descent. 171 5

A patient with thalassemia minor (TM) is reported who ingested 80 g of alcohol/day and presented an important overload of iron with deposits and a hepatic iron ratio compatible with primary hemochromatosis. The results obtained from the study of histocompatibility antigens, clinical manifestations and family analysis discarded the possibility of two genetic diseases, beta-thalassemia and primary hemochromatosis, being concomitantly present in the same progeny. Thalassemia minor and alcoholic hepatopathy are considered as having acted together and being responsible for the iron overload. The relation between alcohol ingested, TM and iron deposits is discussed.
 ...
PMID:[Thalassemia minor with iron overload: genetic and clinical study of a family]. 176 61

The kinetics of hemolysis of erythrocytes in glycerol-containing media was studied spectrophotometrically. The hemolytic process starts by a rapid process, obeying a first order rate law, which is followed by a slow change in absorbance. The kinetics of hemolysis may be described by (a) the maximum absorption, Emax, due to cellular expansion, (b) the rate constant, k, of the fast process and (c) the final absorption at its end, Einf and the ratio Einf/Emax. At pH 6.85 in normal human cells, k = 0.72 min-1 while in hereditary spherocytosis cells, k = 1.06 min-1, iron deficiency k = 0.52 and beta-thalassemia minor k = 0.36 min-1. The percentages of Einf/Emax were 35.3 in control cells, while they were 9.8, 50.0 and 88.3 in spherocytosis, iron deficiency and thalassemia, respectively. Thus these kinetic parameters may help to distinguish and understand the above mentioned erythrocyte disorders. At physiological pH (7.4-7.2), no hemolysis was detected in the medium used. When the pH decreased, hemolysis occurred, its rate increasing gradually until pH 6.3. On further acidosis, the hemolytic rate slowed down again. Addition of DIDS to the whole blood prior to the test inhibits hemolysis. Similar effect of DIDS was noted in washed cells; this effect was partially reversed by albumin. These results suggest that a process involving band 3 affects the rate and degree of glycerol-induced hemolysis of normal red blood cells.
 ...
PMID:Kinetics of hemolysis of normal and abnormal red blood cells in glycerol-containing media. 201 19

There were altogether 68 patients suffered from beta-thalassemia in the Veterans General Hospital from 1979 to 1986. However only 18 patients had abnormal roentgenologic findings. They were 7 males and 11 females. Their ages ranged from 8 months to 47 years with an average of 13 years. Clinically beta-thalassemia was divided into 3 types: 1) thalassemia major, 2) thalassemia intermediate, 3) thalassemia minor. The osteoporosis, hepatosplenomegaly, and extramedullary hematopoiesis with pseudo-tumor formation. We concluded that the roentgenologic manifestation of the patient was more in patients with major or intermediate type.
 ...
PMID:[The relationship of clinical severity and roentgenologic findings in beta thalassemia]. 227 71

In order to estimate the validity of the discriminant function suggested by England e Fraser, we have determined the number of red cells (RBC) mean cell volume (MCV), hemoglobin mean concentration (MCV) and red cells distribution (RDW) in normal subjects, iron-deficient patients and uncomplicated thalassemia minor. The results obtained allow us to point out that RDW in the patients with thalassemia are higher than in normal subjects. In patients with iron-deficiency, instead, RDW medium is increased, but with a remarkable distribution of values. These results point out that anisocytosis is higher in iron-deficiency than in thalassemia.
 ...
PMID:[Differential erythrocyte parameters in thalassemia minor and hyposideremic syndromes]. 240 79

Haematological data on children with mild iron deficiency-anaemia are compared with those of patients with heterozygous beta-thalassemia. The differential diagnosis of beta-thalassemia minor may suspected on the grounds of the blood smear. Confirmation of the diagnosis is based on the MCV, HbA2 and the graphic determination of EVR50 as well as by family survey. With these simple methods beta-thalassemia minor may be diagnosed with reasonable certainty even in the absence of a special laboratory for the determination of the beta-chain deficiency of hemoglobin. The importance of the correct differential diagnosis is stressed because of the danger of unnecessary iron therapy in thalassemia.
 ...
PMID:[Erroneous diagnosis of iron deficiency anemia]. 248 26

Adenosine triphosphate (ATP) and adenosine diphosphate levels are decreased in erythrocytes from individuals with beta-thalassemia minor. Because 5-phosphoribosyl-1-pyrophosphate (PRPP) is an essential precurosr of adenine nucleotides, we tested the hypothesis that impaired PRPP synthesis is a mechanism for the decreased adenine nucleotide content. Erythrocyte PRPP synthetase activity was significantly decreased, and the Michaelis-Menten constant (Km) for ribose-5-phosphate (R5P) was significantly increased in individuals with alpha-thalassemia minor and those with beta-thalassemia minor. Intact erythrocytes from individuals with alpha-thalassemia and those with beta-thalassemia minor also had an impaired rate of PRPP formation. Both the decrease in PRPP synthetase activity and the impaired PRPP formation were also found in erythrocytes with microcytosis resulting from iron deficiency, indicating that these phenomena may not be specific to thalassemia minor. In all individuals examined, the rate of PRPP formation correlated with ATP content, suggesting that either (1) PRPP synthetase activity is a determinant of ATP content or (2) ATP content is a determinant of PRPP synthetase activity. The depletion of ATP from normal erythrocytes did not affect PRPP synthetase activity, suggesting that ATP content is not a determinant of PRPP synthetase activity. However, a decrease in PRPP synthetase activity did cause an impairment in the rate of adenine nucleotide synthesis, suggesting that PRPP synthetase activity is a determinant of ATP content. Taken together, our results suggest that the decrease in PRPP synthetase activity and the resulting impairment in the rate of PRPP formation are mechanisms for the decreased adenine nucleotide content in thalassemic erythrocytes.
 ...
PMID:Decreased erythrocyte phosphoribosylpyrophosphate synthetase activity and impaired formation in thalassemia minor: a mechanism for decreased adenine nucleotide content. 254 52

Iron deficiency in pregnant women affected with beta-thalassemia minor and minima shows the need for prompt iron treatment. Some notes on the relationship between pregnancy and thalassemia are reported.
 ...
PMID:[Iron therapy in patients with beta-thalassemia minor and minima in pregnancy]. 273 39

The incidence of alpha-thalassemia trait (alpha-thal-1 and alpha-thal-2) among Southern Chinese in Hong Kong is about 3%. From June 1983 to September 1987, prenatal diagnosis for homozygous alpha-thal-1 was performed in 88 pregnancies at risk, using direct DNA analysis of amniotic fluid cells or chorionic villi. Twenty-one homozygous alpha-thal-1 fetuses were aborted and confirmed as Hb Bart's hydrops fetalis, and two were "Hb H" hydrops fetalis. Of 47 pregnancies delivered, 26 were alpha-thal-1 heterozygotes, 10 normal, eight alpha-thal-1/normal. Twenty-one pregnancies, diagnosed as alpha-thal-1/normal, await delivery. Based on a 6% incidence of beta-thalassemia minor among pregnant women in Hong Kong, the number of pregnancies at risk for beta-thalassemia major should be 288 per annum. However, since February 1984, only 25 diagnoses were performed. Comprehensive screening and education programs need to be implemented. The majority of beta-thalassemia defects in Southern Chinese are point mutations, single nucleotide insertions or minor deletions, not detectable by standard gene mapping techniques. With linkage analysis of the defective gene to polymorphic restriction sites, a definitive diagnosis can be obtained in 50% of the families, while in the remaining there is a 50% exclusion rate. We routinely use the Hind III-3' beta, Bam HI-3' beta, Ava II-beta, and Hinc II-psi beta sites for linkage analysis. For first pregnancies, the marked linkage disequilibrium of the Bam HI polymorphism can be applied in 29% of the cases. In nonconclusive cases, fetal blood beta/gamma globin chain synthetic ratio was used.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Prenatal diagnosis of alpha- and beta-thalassemias: experience in Hong Kong. 320 16

We have previously described an English family with gamma delta beta-thalassemia in which a large deletion stops 25 kilobases (kb) upstream from the beta-globin gene locus, and yet the beta-globin gene is inactive in vivo. Affected family members had a beta-thalassemia minor phenotype with a normal hemoglobin A2 level. Gene mapping showed that these subjects were heterozygous for a chromosome bearing a large deletion that began in the G gamma-globin gene, extended through the epsilon-globin gene, and continued upstream for at least 75 kb. The A gamma-, delta-, and beta-globin gene loci on this chromosome were intact. To examine the possibility that an additional defect was present in the beta-globin gene, we cloned, sequenced, and examined the expression of the beta-globin gene from the affected chromosome. No mutation was found in the beta-globin gene sequence from 990 base-pairs 5' to the cap site to 350 basepairs 3' to the polyadenylation signal. The gene was subcloned into an expression vector and introduced into HeLa cells. Analysis of RNA derived from these cells, using a ribonuclease protection assay, revealed qualitatively and quantitatively normal transcription. Thus a structurally and functionally normal beta-globin gene is inactive in the presence of a large deletion more than 25 kb upstream. The loss of beta-globin gene function may be due to disturbance of chromatin conformation caused by the deletion or may be the result of loss of upstream sequences that are necessary for beta-globin gene expression in vivo.
 ...
PMID:The inactive beta globin gene on a gamma delta beta thalassemia chromosome has a normal structure and functions normally in vitro. 334 45


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>