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)

In order to evaluate the feasibility of using quantitative polymerase chain reaction (PCR) to evaluate gene dosage, we developed an assay to detect alpha-globin genes, which are frequently deleted in alpha-thalassemia patients. In this quantitative assay alpha-1 and alpha-2 globin consensus regions are coamplified by one oligonucleotide pair, along with a second primer pair targeting a single-copy reference gene, namely, tumor necrosis factor alpha, or TNF-alpha. A series of DNA samples titrating alpha-globin against TNF-alpha DNA have a strong linear relationship between template ratios and product ratios (r > 0.98). Minimal sequence divergence (91% homology) between alpha-1 and alpha-2, internal to the identical primer annealing sites, results in a lower amplification efficiency for alpha-1, to 94% of alpha-2 for each cycle. Furthermore, when applied to a variety of individual DNA samples, the signal ratios of alpha-globin to TNF-alpha were far more variable than previously observed for titrated control DNA. We conclude that DNA isolates from different individuals may have idiosyncratic changes in amplification efficiency owing to polymorphic sequence variation and/or variable presence of unidentified contaminants. Despite these potentially confounding factors, however, we were able to identify by quantitative PCR a single gene deletion later confirmed by Southern blot analysis in 20 individual DNA samples.
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PMID:Evaluation of gene deletions by quantitative polymerase chain reaction. Experience with the alpha-thalassemia model. 786 34

Patients with beta-thalassemia major (beta-thalassemia) frequently have bone disorders of multifactorial etiology. We attempted to analyze the relationship between the bone mineral density ([BMD] measured by dual-photon absorptiometry) and auxanologic parameters, degree of siderosis, function of the growth hormone (GH)/insulin-like growth factor-I (IGF-I)/IGF-binding protein-3 (IGFBP3) axis, calcium-phosphate balance, parathyroid hormone (PTH), and cytokines (interleukin-1beta [IL-1] and tumor necrosis factor-alpha [TNF-alpha]) in 30 prepubertal children with beta-thalassemia major and 15 age-matched children with constitutional short stature (CSS), who have normal glucose tolerance and thyroid function. Children with beta-thalassemia had a significantly decreased BMD and mean BMD% for age and sex (0.75+/-0.24 g/cm2 and 71%+/-10%, respectively) versus children with CSS (1.06+/-0.3 g/cm2 and 92%+/-7%, respectively). Thalassemic patients had significantly lower circulating concentrations of IGF-I and IGFBP3 (49+/-21 ng/mL and 1.2+/-0.25 mg/L, respectively) compared with control children (153+/-42 ng/mL and 2.1+/-0.37 mg/L, respectively). The GH response to provocation by clonidine and glucagon was defective (peak GH < 7 microg/L) in 12 of the 30 thalassemic children. Serum concentrations of IL-1beta and TNF-alpha did not differ among the two study groups. Hypocalcemia was detected in five of the 30 thalassemic patients: hypoparathyroidism was diagnosed in two of the five and rickets in the other three. BMD was highly correlated with the circulating concentrations of IGF-I and IGFBP3, as well as with the auxanologic parameters (age, weight, height, height standard deviation score [HSDS], and body mass index [BMI]). It is suggested that increasing the circulating IGF-I concentration through aggressive nutritional therapy and/or GH/IGF-I therapy with supplementation with vitamin D and/or calcium might improve bone growth and mineralization and prevent the development of osteoporosis and consequent fractures in these patients. Such therapy requires blinded controlled trials.
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PMID:Bone mineral density in prepubertal children with beta-thalassemia: correlation with growth and hormonal data. 959 44

The development of genetic epidemiology methods using recent human genetic map together with the growing availability of candidate genes have led to substantial advances in the identification of host genes in human malaria. Investigation of these genes has progressed along two complementary ways: 1) The search for genes influencing the severe malaria clinical phenotype by means of population based case-control studies which showed the protective role of several red cell genetic defects (sickle cell anemia, a-thalassaemia ...) and that some polymorphisms of the TNF-alpha promoter region could predispose to cerebral malaria; 2) The investigation of the genetic regulation of malaria-related biological phenotypes (infection levels, immune response) by means of familial studies which underlined the influence of the 5q31-q33 chromosomal region in the control of Plasmodium falciparum blood parasitemia and the role of major histocompatibility complex (MHC) and non-MHC genes in the regulation of humoral and cellular response to various malarial antigens. Ongoing studies will precise the role of these genes and probably reveal the existence of other genes not identified yet. The impact of these findings on the understanding of malaria pathogenesis and on the design of future preventive and therapeutic strategies should be considerable.
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PMID:[Genetic epidemiology in the study of susceptibility/resistance to malaria in the human population]. 1057 61

The aim of the study was to examine the effects of endurance exercise on circulating vascular cell adhesion molecule-1 (sVCAM-1) and intercellular adhesion molecule-1 (sICAM-1) in sickle cell trait (SCT) athletes with or without alpha-thalassemia. Five athletes with SCT, 7 athletes with both SCT and alpha-thalassemia (SCTAT) and 8 control athletes (CONT) performed an incremental test on cycloergometer followed 72 hours later by a 60-min endurance exercise with a workload set at 70% P(peak) (peak power). We assessed levels of sICAM-1, sVCAM-1 and TNF-alpha at rest, immediately after endurance exercise and 1, 2, and 24 hours of recovery. Although, CONT and SCTAT groups exhibited similar basal plasma levels of adhesion molecules and TNF-alpha, SCT group had higher sVCAM-1 basal concentrations. No significant variation in sVCAM-1, sICAM-1 and TNF-alpha was measured following endurance exercise. Consequently, sVCAM-1 remained elevated in the SCT group after exercise and during the recovery period. In conclusion, our findings support the concept that SCT athletes might be at risk for microcirculatory disturbances, but these adhesive processes were not further impaired in response to endurance exercise. In addition, alpha-thalassemia co existing trait may be protective both at rest and after endurance exercise in SCT subjects.
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PMID:Plasma levels of adhesion molecules ICAM-1 and VCAM-1 in athletes with sickle cell trait with or without alpha-thalassemia during endurance exercise and recovery. 1902 34

Malaria causes more than one million deaths annually, worldwide. Understanding the genetic defenses against this disease is an important challenge for science. We know that the long-term presence of endemic malaria has led to a prevalence of the beta degrees 39 heterozygous thalassemia mutation in the two islands of Corsica and Sardinia. The populations of both islands are isolated, which could make it easier to find other genetic traits selected by disease pressure. We chose to investigate genes implicated in the primary defenses against Plasmodium falciparum: oxidative metabolism and the immune response. We indeed selected genes coding for nitric oxide synthase 2 (NOS2 promoter, polymorphisms NOS2(AAAT) I/D and NOS2(CCTTT)n) and genes coding for tumor necrosis factor-alpha (TNFA 3'UTR, polymorphisms TNFd(GA)n and TNFe(GA)n). Some associations of TNFA alleles or haplotypes were found either with or without the beta degrees 39 mutation, suggesting a complex link originally between TNF-alpha and resistance or susceptibility to infection.
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PMID:TNFA locus is associated with beta degrees 39 thalassemia in Corsica and Sardinia. 1910 26

Regular blood transfusions in transfusion-dependent thalassemia (TDT) patients can lead to iron overload, causing oxidative stress and sympathovagal imbalance, resulting in increased cardiac complications. We hypothesized that administrating of N-acetylcysteine (NAC) prevents serious adverse events including cardiac complications in TDT patients by reducing systemic oxidative stress and balancing cardiac sympathovagal control. This study was double-blind, randomized control trial, investigating in 59 Thai TDT patients. After randomization, the participants were divided into two groups. The control group received standard care of TDT patient plus placebo, whereas the intervention group received 600 mg of NAC orally for six months. Serum 8-isoprostane, TNF-alpha, IL-10, 24-hour ECG monitoring, echocardiograms and the incidence of thalassemia-related complications were collected. At baseline, no significant difference in any parameters between the control and the intervention groups. At the end of intervention, the incidence of serious adverse events (i.e. infection, worsening thalassemia) was significantly higher in the control group when compared with the intervention group (24.1% vs. 3.3%, p=0.019) (Chi-square test; absolute risk reduction=20.8%, number needed to treat=4.8). The control group also had significantly lower time-dependent HRV parameters, compared with the intervention group (p=0.025 and 0.030, independent t-test). Treatment with NAC restored HRV and reduced serious adverse event in TDT patients, however, no difference in cardiac complications could be demonstrated. NAC could prevent serious adverse events in TDT patients. The proposed mechanism might be the balancing of sympathovagal control.
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PMID:N-acetylcysteine Restored Heart Rate Variability and Prevented Serious Adverse Events in Transfusion-dependent Thalassemia Patients: a Double-blind Single Center Randomized Controlled Trial. 3254 10