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)

Patients with beta-thalassemia (thal) major are subject to peroxidative tissue injury by iron overload. Glutathione S-transferases work as antioxidants, and their activity is determined genetically. In this study, we used multiplex polymerase chain reaction (m-PCR) to analyze polymorphisms of two endogenous antioxidant agents, glutathione S-transferase M1 (GSTM1) and glutathione S-transferase T1 (GSTT1), and to determine their roles in 41 patients with beta-thal major. Our results showed that the GSTM1 and GSTT1 null genotypes were not associated with any incidence of endocrine dysfunction (including diabetes mellitus, hypogonadism, hypothyroidism, and growth hormone deficiency), liver function, or impaired left ventricular ejection fraction (LVEF). The GSTM1 null genotype, but not the GSTT1 null genotype, was associated with a decreased signal intensity ratio on cardiac magnetic resonance imaging (MRI). Our results suggest that genetic variations of the GSTM1 enzyme are associated with cardiac iron deposition in patients with beta-thal major.
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PMID:Glutathione S-transferase M1 gene polymorphisms are associated with cardiac iron deposition in patients with beta-thalassemia major. 1679 50

beta-thalassemia (beta-thal) is characterized by disturbances of the reproductive system. The aim of the present study was: 1) to assess the hypothalamic- pituitary-gonadal axis in patients with beta-thal in relation to their phenotype and 2) to determine prognostic features of current gonadal status. We studied 135 patients (67 males and 68 females) with beta-thal through history, physical examination, spermiograms and GnRH test. These patients were divided into beta-thal major (51 males and 62 females) and beta-thal intermedia phenotypes (16 males and 6 females). Male patients with beta-thal major were subdivided into three groups a) eugonadal (35%, Tanner's stage V, normal testicular volume, normal spermiograms, normal basal and stimulated hormone values), b) patients with hypogonadotrophic hypogonadism (HH) of late onset (24%, Tanner's stage II-V, low-normal testicular volume, abnormal spermiograms, normal basal gonadotrophin values and abnormal response to GnRH test) and c) patients with HH of early onset (41%, Tanner's stage I, small testicular volume, abnormal spermiograms, abnormal basal and stimulated hormone values). Female patients with beta-thal major were subdivided into: a) eugonadal (32%, Tanner's stage V, regular menstruation, normal basal and stimulated hormone values), b) patients with hypogonadotrophic hypogonadism (HH) of late onset (34%, Tanner's stage II-V, secondary amenorrhea, subnormal basal and stimulated gonadotrophin values) and c) patients with HH of early onset (34%, Tanner's stage I, primary amenorrhea, subnormal basal and stimulated hormone values). Patients with beta-thal intermedia were subdivided into eugonadal (75% of males, 33% of females) and hypogonadal (25% of males, 67% of females). Current gonadal status could not be predicted by means of transfusion or chelation parameters. In conclusion, beta-thal patients could be eugonadal or develop early or late onset HH. trade mark-thal intermedia patients have a more favorable profile than beta-thal major individuals. Current gonadal status of beta-thal patients cannot be predicted by means of history, clinical or laboratory parameters.
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PMID:beta-thalassemia and gonadal axis: a cross-sectional, clinical study in a Greek population. 1701 46

Iron-overload associated endocrinopathy is the most frequently reported complication of chronic transfusion therapy in patients with thalassaemia (Thal). This study compared iron-overloaded subjects with Thal (n = 142; 54%M; age 25.8 +/- 8.1 years) and transfused sickle-cell disease (Tx-SCD; n = 199; 43%M, 24.9 +/- 13.2 years) to non-transfused SCD subjects (non-Tx-SCD; n = 64, 50%M, 25.3 +/- 11.3 years), to explore whether the underlying haemoglobinopathy influences the development of endocrinopathy. Subjects were recruited from 31 centres in the USA, Canada and the UK. Subjects with Thal had more evidence of diabetes (13% vs. 2%, P < 0.001), hypogonadism (40% vs. 4%, P < 0.001), hypothyroidism (10% vs. 2%, P = <0.001) and growth failure (33% vs. 7%, P < 0.001), versus Tx-SCD. Fifty-six per cent of Thal had more than one endocrinopathy compared with only 13% of Tx-SCD (P < 0.001). In contrast, Tx-SCD was not different from non-Tx-SCD. Multivariate analysis indicated that endocrinopathy was more likely in Thal than SCD [Odds Ratio (OR) = 9.4, P < 0.001], with duration of chronic transfusion a significant predictor (OR = 1.4 per 10 years of transfusion, P = 0.04). Despite iron overload, endocrinopathy was not increased in Tx-SCD versus non-Tx-SCD, suggesting that the underlying disease may modulate iron-related endocrine injury. However, because transfusion duration remained a significant predictor of endocrinopathy, these data should be confirmed in SCD subjects that have been chronically transfused for longer periods of time.
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PMID:Increased prevalence of iron-overload associated endocrinopathy in thalassaemia versus sickle-cell disease. 1705 76

Hypogonadism, resulting from iron-induced pituitary dysfunction, is the most frequently reported complication in patients with beta-thalassaemia major. The aim of this study was to evaluate pituitary Magnetic Resonance Imaging (MRI) signal intensity reduction, on T2*-weighted images, as a marker of pituitary iron overload. Thirty patients (13 females and 17 males, mean age: 16.6+/-4.1) with beta-thalassaemia major on conventional treatment and 13 healthy volunteers (7 females and 6 males, mean age: 11+/-4.51 years) were studied with T2*-weighted images of the anterior pituitary using a 1.5T unit. Four thalassaemic patients (2 females and 2 males) had clinical hypogonadism and required hormonal replacement treatment. Results revealed a statistically significant reduction of pituitary signal intensity in the thalassaemia group compared to controls (p<0.001). Moreover, hypogonadal patients had significantly decreased MRI values compared to thalassaemic patients without hypogonadism (p=0.017). Relatively decreased adeno-hypophyseal MRI signal intensity was recorded in pubertal thalassaemic patients. A significant negative correlation was observed between pituitary MRI values and age (r=-0.67, r(2)=0.443, p=0.001), whereas ferritin levels and pituitary MRI values were moderately correlated (r=-0.56, r(2)=0.32, p=0.08) in adult thalassaemic patients. In conclusion, pituitary MRI indices as measured on T2*-weighted images seem to reflect pituitary iron overload and could, therefore, be used for a preclinical detection of patients who are in greater danger of developing hypogonadism.
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PMID:MRI for the determination of pituitary iron overload in children and young adults with beta-thalassaemia major. 1716 70

Hemolytic anemias can induce various anomalies of the endocrine glands which can already be observed in children. Endocrine dysfunction is also found in the course of therapy for aplastic anemias, usually as undesirable side effects. In Europe, 2-9% of the population belongs to ethnic minorities at risk for developing hemolytic anemia. Pituitary affinity to iron deposition explains the high incidence of hypogonadism, puberty delay and growth retardation although other factors have to be considered. Growth hormone deficiency has to be ruled out as it can occur in a minority of subjects with thalassemia and sickle-cell disease (drepanocytosis). Diabetes mellitus, hypothyroidism and hypoparathyroidism may also develop. Follow-up includes close monitoring of growth and pubertal development in order to guide therapeutic interventions.
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PMID:[Severe chronic anemia and endocrine disorders in children]. 1752 72

Reduced serum insulin-like growth factor-1 (IGF-1) and hypogonadotrophic hypogonadism are common features of adult beta-thalassemia, and warrant evaluation of the growth hormone (GH)-IGF-1 axis. The aim of this study was to determine GH reserve in beta-thalassemia patients (9 females, 7 males, 15 major, 1 intermedia), age 29.3 +/- 6.9 years, BMI 21.3 +/- 1.9 kg/m2, and in 20 age, sex and BMI-matched healthy controls, using the GH-releasing hormone (GHRH)-arginine test. The associations between peak GH response and hormonal and biochemical indices were evaluated. Using BMI-related cut-off limits for peak GH response in the GHRH-arginine test, 4/16 beta-thalassemia patients had peak GH lower than 11.5 microg/l, the cut-off limit suggested for lean subjects, and were diagnosed as GH deficient (GHD). Using 9 microg/l as the cut-off limit 2/16 patients were GHD. Reduced serum IGF-1 and IGFBP-3 were present in 69% and 19% of the patients, respectively. Peak GH did not correlate with serum IGF-1, TSH, and fT4 levels or gonadal status. Neither peak GH nor IGF-1 correlated with serum ferritin. Our findings suggest that GHD is present in up to a quarter of adult beta-thalassemia patients. The clinical benefits of GH therapy need to be determined. GHD alone does not account for the high prevalence of reduced IGF-1 in adult beta-thalassemia.
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PMID:Growth hormone reserve in adult beta thalassemia patients. 1770 95

Patients with multi-transfused thalassaemia major may develop severe endocrine complications due to iron overload. The anterior pituitary is particularly sensitive to iron overload which disrupts hormonal secretion resulting in hypogonadism, short stature , acquired hypothyroidism and hypoparathyroidism. Glucose intolerance and diabetes mellitus are also common in thalassaemic patients. The severity of the clinical manifestation and laboratory findings in thalassaemia largely depends on the genotype; thus homozygotes or compound heterozygotes for the mutations beta0 or beta+ depend for life on frequent transfusions. A multicenter study in Cyprus including 435 patients showed hypogonadotrophic hypogonadism in 32.5%, short stature in 35%, acquired hypothyroidism in 5.9%, hypoparathyroidism in 1.2% and diabetes mellitus in 9.4%. A slowing down of growth velocity and a reduced or absent pubertal growth spurt is observed in early adolescence leading to short adult height. Delayed or absent puberty and hypogonadism may result in fertility problems which affect enormously the life of thalassemics. Glucose intolerance in adolescence and diabetes mellitus later in life are also frequent complications mainly due to iron overload, chronic liver disease and genetic predisposition. Primary hypothyroidism and hypoparathyroidsm usually appear in the second decade of life; are related to iron overload and may be reversible at an early stage by intensive chelation. Osteopenia and osteoporosis due to a complicated pathogenesis represent prominent causes of morbidity in young adults of both genders with thalassaemia. Early recognition and prevention of the endocrine complications, by early and regular chelation therapy, is mandatory for the improvement of the quality of life and psychological outcome of these patients.
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PMID:Endocrine complications in patients with Thalassaemia Major. 1808 58

Adults with beta thalassemia major frequently have low BMD, fractures, and bone pain. The purpose of this study was to determine the prevalence of low BMD, fractures, and bone pain in all thalassemia syndromes in childhood, adolescence, and adulthood, associations of BMD with fractures and bone pain, and etiology of bone disease in thalassemia. Patients of all thalassemia syndromes in the Thalassemia Clinical Research Network, > or =6 yr of age, with no preexisting medical condition affecting bone mass or requiring steroids, participated. We measured spine and femur BMD and whole body BMC by DXA and assessed vertebral abnormalities by morphometric X-ray absorptiometry (MXA). Medical history by interview and review of medical records, physical examinations, and blood and urine collections were performed. Three hundred sixty-one subjects, 49% male, with a mean age of 23.2 yr (range, 6.1-75 yr), were studied. Spine and femur BMD Z-scores < -2 occurred in 46% and 25% of participants, respectively. Greater age, lower weight, hypogonadism, and increased bone turnover were strong independent predictors of low bone mass regardless of thalassemia syndrome. Peak bone mass was suboptimal. Thirty-six percent of patients had a history of fractures, and 34% reported bone pain. BMD was negatively associated with fractures but not with bone pain. Nine percent of participants had uniformly decreased height of several vertebrae by MXA, which was associated with the use of iron chelator deferoxamine before 6 yr of age. In patients with thalassemia, low BMD and fractures occur frequently and independently of the particular syndrome. Peak bone mass is suboptimal. Low BMD is associated with hypogonadism, increased bone turnover, and an increased risk for fractures.
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PMID:Bone disease in thalassemia: a frequent and still unresolved problem. 1850 76

Frequent blood transfusions can lead to iron overload which may result in several endocrine complications especially in the absence of adequate chelation therapy. The objectives of this study are to determine the prevalence of endocrine complications in transfusion dependent thalassaemia patients and the correlation of endocrine complications with the degree of iron chelation. This retrospective study looked at cases of adult patients with transfusion dependent thalassaemia treated in the Haematology Unit, Penang Hospital. Of the 25 transfusion dependent thalassaemia patients, there were 10 male and 15 female patients respectively with almost equal number of Malay and Chinese patients (13 and 12 patients respectively). Short stature was seen in 36.0% of our patients. In our cohort, 12 patients had delayed puberty (male 70.0% and female 33.3%). Prevalence of osteoporosis was 36.0%. Hypogonadism was noted in 40.0% of males and 46.7% of females. 53.4% of the female population had menstrual abnormalities with prevalence of primary and secondary amenorrhoea at 26.7% each. The prevalence of other endocrinopathies was much lower: 8.0% had diabetes mellitus and only one patient had hypocortisolism. Iron chelation appeared insufficient in our study population. The high frequency of endocrine complications noted in our study supports the rationale for regular follow-up of transfusion dependent thalassaemic patients to ensure early detection and timely treatment of associated complications.
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PMID:Endocrine complications in transfusion dependent thalassaemia in Penang Hospital. 1894 94

273 patients with thalassaemia major followed from diagnosis in the Ferrara Centre were divided into 3 cohorts (C) according to the year of birth (C1=1954-1964, 85 patients; C2=1965-1974, 129 patients; C3=1975-2001, 59 patients) in order to study the trends of endocrine complications. Menarche occurred in 52 out of 112 patients (46%), without significant differences among the 3 groups, at the mean age of 13.9+/-1.4 years. Sixty-five percent of these patients had secondary amenorrhoea at the mean age of 18.8+/-3.7 years. In males complete pubertal development occurred in 48% of patients (C1:31%, C2: 44%, C3: 63%, p<0.05) followed by secondary hypogonadism in 24% of patients above 21 years of age. Primary (80%) and central 20%) hypothyroidism were diagnosed in 31% of patients (C1: 55%, C2: 31.5%, C3: 13.4%, p<0.05), diabetes mellitus (DM) in 17% of patients (C1: 28.6%, C2: 17.2%, C3: 3.4%, p<0.05), and hypoparathyroidism in 10.6% of cases (C1: 18.7%, C2: 10.1%, C3: 3.4%, p<0.05). No difference was found in patient mean age of diagnosis of hypothyroidism, DM or hypoparathyroidism (20.4+/-8.2 years, 19+/-5 yrs and 18.5+/-5.8 yrs respectively) but in all three groups age at diagnosis significantly increased over time (hypothyroidism and DM: p<0.001; hypoparathyroidism: p<0.01). Over time the prevalence of hypothyroidism, diabetes mellitus and hypoparathyroidism increased to 24.4%, 14.7%, and 6.7%, respectively, at the time of the study. Incidences peaked in the early 1980's, and declined in the following years (primary hypothyroidism from 6.5% in 1981 to 0.9% in 2007, p<0.01; DM from 3.9% in 1986 to 0.8% in 2007, p<0.05; hypoparathyroidism 2.4% in 1984 to 0% in 2007, p<0.01) and correlated with the decrease in annual mean serum ferritin levels in all patients (p<0.001). The main risk factors associated with endocrine complications were high serum ferritin levels, poor compliance with desferioxamine (DFO) therapy, early onset of transfusion therapy (only for hypogonadism) and splenectomy (only for hypothyroidism). Serum ferritin levels of approximately 2000 ng/ml were found to correlate with hypogonadism, and 3000 ng/ml for hypothyroidism, hypoparathyroidism and DM. The incidences of hypothyroidism, DM and hypoparathyroidism were not significantly different in 18 patients on long term treatment with deferiprone (DPO) compared with 64 patients continuously treated with DFO, from 1995 to 2007. In conclusion, our longitudinal study shows that in the last 30 years in the Ferrara Centre the incidences of hypothyroidism, diabetes mellitus, and hypoparathyroidism declined, and pubertal development in males with thalassemia major improved in patients, on DFO treatment, born after 1976. The efficacy of alternative chelation regimes with deferiprone or deferasirox to monotherapy with desferioxamine remains to be established.
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PMID:Hypogonadism, diabetes mellitus, hypothyroidism, hypoparathyroidism: incidence and prevalence related to iron overload and chelation therapy in patients with thalassaemia major followed from 1980 to 2007 in the Ferrara Centre. 1933 72


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