1/15. A novel mutation in the thiamine responsive megaloblastic anaemia gene SLC19A2 in a patient with deficiency of respiratory chain complex I.The thiamine transporter gene SLC19A2 was recently found to be mutated in thiamine responsive megaloblastic anaemia with diabetes and deafness (TRMA, Rogers syndrome), an early onset autosomal recessive disorder. We now report a novel G1074A transition mutation in exon 4 of the SLC19A2 gene, predicting a Trp358 to ter change, in a girl with consanguineous parents. In addition to the typical triad of Rogers syndrome, the girl presented with short stature, hepatosplenomegaly, retinal degeneration, and a brain MRI lesion. Both muscle and skin biopsies were obtained before high dose thiamine supplementation. While no mitochondrial abnormalities were seen on morphological examination of muscle, biochemical analysis showed a severe deficiency of pyruvate dehydrogenase and complex I of the respiratory chain. In the patient's fibroblasts, the supplementation with high doses of thiamine resulted in restoration of complex I activity. In conclusion, we provide evidence that thiamine deficiency affects complex I activity. The clinical features of TRMA, resembling in part those found in typical mitochondrial disorders with complex I deficiency, may be caused by a secondary defect in mitochondrial energy production.- - - - - - - - - - ranking = 1keywords = diabetes (Clic here for more details about this article) |
2/15. Thiamine-responsive megaloblastic anemia syndrome (TRMA) with cone-rod dystrophy.Thiamine-responsive megaloblastic anemia (TRMA) is an autosomal recessive disease in which the active thiamine uptake into cells is disturbed. The molecular basis underlying the disorder has been related to mutations in the gene SLC19A2 on chromosome 1q23.3 that encodes a functional thiamine transporter. The protein is predicted to have 12 transmembrane domains. TRMA is characterized by sensorineural deafness, diabetes mellitus, megaloblastic anemia, and cardiomyopathy. optic nerve atrophy and retinal dystrophy have been reported in a small number of patients. We report a 15-year-old girl with TRMA and cone-rod dystrophy and confirm that retinal dystrophy may form part of the syndrome. Differential diagnosis of syndromes with deafness, diabetes mellitus, and optic nerve atrophy or retinal dystrophy are discussed. The authors suggest that ERG be performed in all patients with TRMA.- - - - - - - - - - ranking = 13.39784828231keywords = diabetes mellitus, mellitus, diabetes (Clic here for more details about this article) |
3/15. A novel mutation in the SLC19A2 gene in a Tunisian family with thiamine-responsive megaloblastic anaemia, diabetes and deafness syndrome.Thiamine-responsive megaloblastic anaemia (TRMA) syndrome with diabetes and deafness was found in two patients from a Tunisian kindred. The proband was homozygous for a novel mutation, 287delG, in the high-affinity thiamine transporter gene, SLC19A2. We demonstrated that fibroblasts from this patient exhibited defective thiamine transport. These data confirm that the SLC19A2 gene is the high-affinity thiamine carrier and that this novel mutation is responsible for TRMA syndrome.- - - - - - - - - - ranking = 5keywords = diabetes (Clic here for more details about this article) |
4/15. Thiamine transport by erythrocytes and ghosts in thiamine-responsive megaloblastic anaemia.A 9-year study of thiamine metabolism and cellular transport was performed in two patients with thiamine-responsive megaloblastic anaemia associated with diabetes mellitus and sensorineural deafness, in their relatives, and in age-matched controls from the same area. The ratios between the content of thiamine and that of its phosphoesters in erythrocytes were within the normal range, whereas the absolute values of thiamine and thiamine compounds were reduced by about 40% as compared to controls. Thiamine pyrophosphokinase activity was about 30% lower than in controls. Thiamine treatment restored the levels of thiamine and thiamine compounds to normal values, whereas kinase was unaffected. Both the saturable (specific, predominant at low, less than 2 mumol/L, physiological concentrations of thiamine) and the non-saturable component of thiamine transport were investigated. erythrocytes and ghosts from patients exhibited no saturable component, this abnormality being specific for the patients and not shared by their parents. It is concluded that the cells from thiamine-responsive megaloblastic anaemia patients contain low levels of thiamine compounds, probably due to their inability to take up and retain physiological concentrations of thiamine, as a result of the lack of the saturable, specific component of transport and reduced thiamine pyrophosphokinase.- - - - - - - - - - ranking = 2.0390224234154keywords = mellitus, diabetes (Clic here for more details about this article) |
5/15. Cardiac manifestations in thiamine-responsive megaloblastic anemia syndrome.Thiamine-responsive megaloblastic anemia (TRMA) syndrome is a rare autosomal recessive disorder defined by the occurrence of megaloblastic anemia, diabetes mellitus, and sensorineural deafness, responding in varying degrees to thiamine treatment. Other features of this syndrome gradually develop. We describe three TRMA patients with heart rhythm abnormalities and structural cardiac anomalies. Eight other reported TRMA patients also had cardiac anomalies. Recently, the TRMA gene, SLC19A2, was identified, encoding a functional thiamine transporter. Characterization of the metabolic defect of TRMA may shed light on the role of thiamine in common cardiac abnormalities.- - - - - - - - - - ranking = 6.6989241411552keywords = diabetes mellitus, mellitus, diabetes (Clic here for more details about this article) |
6/15. Novel mutation in the SLC19A2 gene in an African-American female with thiamine-responsive megaloblastic anemia syndrome.Thiamine-responsive megaloblastic anemia (TRMA) syndrome is an autosomal recessive disorder characterized by diabetes mellitus (DM), progressive sensorineural deafness, and thiamine-responsive anemia. Mutations in the SLC19A2 gene encoding a high-affinity thiamine transporter protein THTR-1 are responsible for the clinical features associated with TRMA syndrome. We report an African-American female with TRMA-syndrome associated with thyroid disease and retinitis pigmentosa caused by a novel mutation in the SLC19A2 gene. The patient presented at 12 months of age with paroxysmal atrial tachycardia and hepatosplenomegaly. One month later, she developed DM requiring intermittent insulin therapy. At 2-1/2 years of age, profound sensorineural hearing loss was discovered. By 4 years of age, daily insulin therapy (0.5 U/kg/day) was instituted and her insulin requirement gradually increased to 1.0 U/kg/day by 9 years of age. She developed optic atrophy, retinitis pigmentosa, and visual impairment by 12 years of age with severe restriction of peripheral vision by 16 years. At age 19, a thiamine-responsive normocytic anemia was discovered. She was diagnosed with autoimmune thyroiditis at 20 years and she experienced a psychotic episode associated with a mood disorder at age 21. With oral thiamine therapy, her insulin requirement decreased by 30% over a 20 month period. Molecular analysis revealed that the patient is homozygous for a missense mutation (C152T) in exon 1 of the SLC19A2 gene.- - - - - - - - - - ranking = 6.6989241411552keywords = diabetes mellitus, mellitus, diabetes (Clic here for more details about this article) |
7/15. Pediatric stroke associated with new onset type 1 diabetes mellitus: case reports and review of the literature.Neurological deterioration in children with diabetic ketoacidosis (DKA) is commonly caused by cerebral edema. However, stroke should also be suspected when focal neurological deficits are apparent, because children with hyperglycemia and DKA are prone to thrombosis. We report three cases of pediatric stroke associated with new onset type 1 diabetes mellitus (T1DM). The first case presented with sinovenous thrombosis, and the other two cases presented in DKA and had a late diagnosis of ischemic stroke following neurological deterioration. Our recent experiences and review of the literature emphasize the importance of early diagnosis, investigation, and treatment for patients that present with new onset T1DM and stroke.- - - - - - - - - - ranking = 33.494620705776keywords = diabetes mellitus, mellitus, diabetes (Clic here for more details about this article) |
8/15. Thiamine responsive anemia: report of a new case associated with a thiamine pyrophosphokinase deficiency.We report a new case of thiamine responsive anemia in a three years old boy with the characteristic association of anemia, diabetes mellitus and deafness. Thiamine therapy corrected anemia as described. A thiamine pyrophosphokinase deficiency (TPK) was found which was not influenced by treatment. However normal levels of thiamine pyrophosphate (TPP) were obtained without correction of all symptoms particularly dyserythropoiesis. Thus, etiology of the syndrome is not only a thiamine pyrophosphokinase deficiency as previously suggested.- - - - - - - - - - ranking = 6.6989241411552keywords = diabetes mellitus, mellitus, diabetes (Clic here for more details about this article) |
9/15. Thiamine-responsive anemia in DIDMOAD syndrome.Two children with the DIDMOAD syndrome (diabetes insipidus, diabetes mellitus, optic atrophy, deafness) developed a megaloblastic and sideroblastic anemia, neutropenia, and borderline thrombocytopenia. plasma thiamine concentration was low in one patient and normal in the other; in both children, thiamine pyrophosphate in erythrocytes and thiamine pyrophosphokinase activity were lower than the lowest values observed in control subjects. A month after institution of treatment with thiamine, the hematologic findings had returned to normal and the insulin requirements had decreased. Withdrawal of thiamine repeatedly induced relapse of the anemia and an increase in insulin requirements. We propose that an inherited abnormality of thiamine metabolism is responsible for the multisystem degenerative disorder known as DIDMOAD syndrome.- - - - - - - - - - ranking = 7.6989241411552keywords = diabetes mellitus, mellitus, diabetes (Clic here for more details about this article) |
10/15. Studies on thiamine metabolism in thiamine-responsive megaloblastic anaemia.We have investigated thiamine metabolism and transport in the erythrocytes of two patients from unrelated families with thiamine responsive megaloblastic anaemia associated with diabetes mellitus and sensorineural deafness. Both patients had low concentrations of thiamine compounds in plasma and red blood cells. When erythrocytes were incubated with thiazole-[2-14C]-thiamine or [35S]-thiamine in vitro, the concentration of label within the cells was markedly reduced compared with controls. In addition, thiamine pyrophosphokinase activity was deficient in haemolysates prepared from the patients. Some relatives of the patients showed abnormal parameters of thiamine status and transport. In both patients treatment with a lipophilic compound corrected the haematological abnormalities and diabetes and in one patient has so far prevented the progression of deafness. We propose that the disorder is caused by an inherited defect of thiamine transport, possibly related to deficient pyrophosphokinase activity, leading to intracellular depletion of active thiamine metabolite derivatives.- - - - - - - - - - ranking = 7.6989241411552keywords = diabetes mellitus, mellitus, diabetes (Clic here for more details about this article) |
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