Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0002871 (anemia)
 52,094 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Maternal iron deficiency during pregnancy induces anaemia in the developing fetus; however, the severity tends to be less than in the mother. The mechanism underlying this resistance has not been determined. We have measured placental expression of proteins involved in iron transfer in pregnant rats given diets with decreasing levels of iron and examined the effect of iron deficiency on iron transfer across BeWo cell layers, a model for placental iron transfer. Transferrin receptor expression was increased at both mRNA and protein levels. Similarly, expression of the iron-responsive element (IRE)-regulated form of the divalent metal transporter 1 (DMT1) was also increased. In contrast, the non-IRE regulated isoform showed no change in mRNA levels. Protein levels of DMT1 increased significantly. Iron efflux is thought to be mediated by the metal transporter protein, IREG1/ferroportin1/MTP1, and oxidation of Fe(II) to Fe(III) prior to incorporation into fetal transferrin is carried out by the placental copper oxidase. Expression of IREG1 was not altered by iron deficiency, whereas copper oxidase activity was increased. In BeWo cells made iron deficient by treatment with desferrioxamine ('deferioxamine'), iron accumulation from iron-transferrin increased, in parallel with increased expression of the transferrin receptor. At the same time, iron efflux also increased, showing a higher flux of iron from the apical to the basolateral side. The data show that expression of placental proteins of iron transport are up-regulated in maternal iron deficiency, resulting in an increased efficiency of iron flux and a consequent minimization of the severity of fetal anaemia.
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PMID:Effect of iron deficiency on placental transfer of iron and expression of iron transport proteins in vivo and in vitro. 1138 98

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.
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PMID:Novel mutation in the SLC19A2 gene in an African-American female with thiamine-responsive megaloblastic anemia syndrome. 1499 41

The intestinal absorption of cadmium (Cd) is influenced by body iron (Fe) status in laboratory animals and humans. In this study we investigated the role of the apical Fe transporter divalent metal transporter 1 (DMT1) and the basolateral Fe exporter metal transporter protein 1 (MTP1) in Cd absorption. Rats were divided into the following groups; an Fe-sufficient (FeS) control group that was fed an FeS diet for 4 weeks (FeS, 4 weeks); an Fe-deficient (FeD) group that was fed an FeD diet for 4 weeks (FeD, 4 weeks); an FeS control group that was fed an FeS diet for 8 weeks (FeS, 8 weeks); an FeD/FeS group that was fed an FeD diet for 4 weeks and then an FeS diet for the following 4 weeks (FeD/FeS, 4 weeks/4 weeks); and an FeD group that was fed an FeD diet for 8 weeks (FeD, 8 weeks). After the 4- and 8-week feeding periods, rats were given a single oral gavage of Cd and were sacrificed 24 h later. The FeD (4 weeks) group developed Fe deficient anemia, but the parameters returned to control levels in the FeD/FeS group (4 weeks/4 weeks). The Cd body burden was greater in FeD (4 weeks) rats compared to FeS control (4 weeks), but returned to control Cd levels in FeD/FeS (4 weeks/4 weeks) rats. In addition, the expression of DMT1 and MTP1 was induced by Fe deficiency in the duodenum of FeD (4 weeks) rats, but was down-regulated to control values in FeD/FeS (4 weeks/4 weeks) rats. The correlation between duodenal DMT1 and MTP1 expression and Cd body burden in rats suggests an important role of DMT1 and MTP1 in Cd absorption.
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PMID:Dietary iron regulates intestinal cadmium absorption through iron transporters in rats. 1529 43

Thiamine responsive megaloblastic anemia syndrome (TRMA), an autosomal recessive disorder caused by the deficiency of thiamine transporter protein, is the association of diabetes mellitus, anemia and deafness. Pharmacological dose thiamine normalizes hematological abnormalities and their effects on the course of diabetes mellitus. We report on 8 years follow up of two siblings with TRMA. They presented in the prepubertal period with diabetic ketoacidosis due to lack of thiamine supplementation for 2 months. Their insulin requirements fell rapidly and disappeared with thiamine therapy. Hematological parameters normalized within 30 days. The diabetic picture is responsive to thiamine treatment in patients with TRMA. Insulin dependent diabetes may occur throughout the pubertal period. If thiamine supplementation is not sufficient, ketoacidosis may develop in patients during the prepubertal period.
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PMID:Thiamine withdrawal can lead to diabetic ketoacidosis in thiamine responsive megaloblastic anemia: report of two siblings. 1855 72

TRPML1 (mucolipin 1, also known as MCOLN1) is predicted to be an intracellular late endosomal and lysosomal ion channel protein that belongs to the mucolipin subfamily of transient receptor potential (TRP) proteins. Mutations in the human TRPML1 gene cause mucolipidosis type IV disease (ML4). ML4 patients have motor impairment, mental retardation, retinal degeneration and iron-deficiency anaemia. Because aberrant iron metabolism may cause neural and retinal degeneration, it may be a primary cause of ML4 phenotypes. In most mammalian cells, release of iron from endosomes and lysosomes after iron uptake by endocytosis of Fe(3+)-bound transferrin receptors, or after lysosomal degradation of ferritin-iron complexes and autophagic ingestion of iron-containing macromolecules, is the chief source of cellular iron. The divalent metal transporter protein DMT1 (also known as SLC11A2) is the only endosomal Fe(2+) transporter known at present and it is highly expressed in erythroid precursors. Genetic studies, however, suggest the existence of a DMT1-independent endosomal and lysosomal Fe(2+) transport protein. By measuring radiolabelled iron uptake, by monitoring the levels of cytosolic and intralysosomal iron and by directly patch-clamping the late endosomal and lysosomal membrane, here we show that TRPML1 functions as a Fe(2+) permeable channel in late endosomes and lysosomes. ML4 mutations are shown to impair the ability of TRPML1 to permeate Fe(2+) at varying degrees, which correlate well with the disease severity. A comparison of TRPML1(-/- )ML4 and control human skin fibroblasts showed a reduction in cytosolic Fe(2+) levels, an increase in intralysosomal Fe(2+) levels and an accumulation of lipofuscin-like molecules in TRPML1(-/-) cells. We propose that TRPML1 mediates a mechanism by which Fe(2+) is released from late endosomes and lysosomes. Our results indicate that impaired iron transport may contribute to both haematological and degenerative symptoms of ML4 patients.
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PMID:The type IV mucolipidosis-associated protein TRPML1 is an endolysosomal iron release channel. 1879 1

Thiamine-responsive megaloblastic anemia syndrome is an autosomal recessive disorder characterized by diabetes mellitus, megaloblastic anemia and sensorineural hearing loss. Mutations in the SLC19A2 gene, encoding a high-affinity thiamine transporter protein, THTR-1, are responsible for the clinical features associated with thiamine-responsive megaloblastic anemia syndrome in which treatment with pharmacological doses of thiamine correct the megaloblastic anemia and diabetes mellitus. The anemia can recur when thiamine is withdrawn. Thiamine may be effective in preventing deafness if started before two months. Our patient was found homozygous for a mutation, 242insA, in the nucleic acid sequence of exon B, with insertion of an adenine introducing a stop codon at codon 52 in the high-affinity thiamine transporter gene, SLC19A2, on chromosome 1q23.3.
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PMID:Thiamine-responsive megaloblastic anemia: early diagnosis may be effective in preventing deafness. 1981 79

Thiamine-responsive megaloblastic anemia (TRMA) syndrome usually associated with diabetes mellitus, anemia and deafness, due to mutations in SLC19A2, encoding a thiamine transporter protein. The onset of disease is usually seen during infancy or at early childhood and most of the TRMA patients are originated from consanguineous families. In this case, we report a 5-month-old boy who had diagnosis of TRMA during evaluations for his anemia and thrombocytopenia. The diagnosis of TRMA should be kept in mind in differential diagnosis of megaloblastic anemia especially in the populations where the consanguinity is frequent.
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PMID:Thiamine-responsive megaloblastic anemia syndrome. 2083 54

X-linked sideroblastic anemia and ataxia (XLSA-A) is a rare cause of early onset ataxia, which may be overlooked due to the usually mild asymptomatic anemia. The genetic defect has been identified as a mutation in the ABCB7 gene at Xq12-q13. The gene encodes a mitochondrial ATP-binding cassette (ABC) transporter protein involved in iron homeostasis. Until now only three families have been reported, each with a distinct missense mutation in this gene. We describe a fourth family with XLSA-A and a novel mutation in the ABCB7 gene.
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PMID:X-linked sideroblastic anemia and ataxia: a new family with identification of a fourth ABCB7 gene mutation. 2239 76

Thiamine responsive megaloblastic anemia syndrome, an autosomal recessive inherited disorder characterized by a triad of anemia, diabetes mellitus and sensorineural deafness is caused by a deficiency of a thiamine transporter protein. The disorder is rare and has not been reported from our community which has high background of consanguinity. We report a six years old girl who presented with diabetes mellitus which remitted after thiamine replacement. The girl in addition had sensorineural deafness, reinopathy, atrial septal defect and megaloblastic anemia which responded to high doses of thymine. This is the first case reported from Kashmir valley and third from India. The presentation and management in such cases is discussed.
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PMID:Thiamine responsive megaloblastic anemia syndrome associated with patent ductus arteriosus: First case report from Kashmir Valley of the Indian subcontinent. 2283 35

The thiamine-responsive megaloblastic anemia syndrome (TRMA) is an autosomal recessive disorder characterized by diabetes mellitus, megaloblastic anemia and sensorineural hearing loss due to mutations in SLC 19A2 that encodes a thiamine transporter protein. The disease can manifest at any time between infancy and adolescence, and not all cardinal findings are present initially. The anemia typically improves significantly with pharmacological doses of thiamine. Variable improvement in diabetes is also noted. However, the hearing loss is apparently irreversible, although a delay in the onset of deafness may be possible. We present a 2-year old girl with non-autoimmune diabetes mellitus and anemia in whom we found a novelc.95T>A (leu32X) mutation in the SLC19A2 gene in this study.Our patient with this new mutation did not suffer from hearing loss.
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PMID:Thiamine-responsive megaloblastic anemia syndrome: a novel mutation. 2287 72


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