Iron-Refractory Iron Deficiency Anemia in an 11-year-old Girl.
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ABSTRACT:
SUBMITTER: Swaminathan N
PROVIDER: S-EPMC9121776 | biostudies-literature | 2021 Jul
REPOSITORIES: biostudies-literature
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Iron-Refractory Iron Deficiency Anemia in an 11-year-old Girl.
Swaminathan Neeraja N Lieberman Scott M SM Bhagavathi Sharathkumar S Sharathkumar Anjali A
Pediatrics in review 20210701 7
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Project description:Iron refractory iron deficiency anemia is a hereditary recessive anemia due to a defect in the TMPRSS6 gene encoding Matriptase-2. This protein is a transmembrane serine protease that plays an essential role in down-regulating hepcidin, the key regulator of iron homeostasis. Hallmarks of this disease are microcytic hypochromic anemia, low transferrin saturation and normal/high serum hepcidin values. The anemia appears in the post-natal period, although in some cases it is only diagnosed in adulthood. The disease is refractory to oral iron treatment but shows a slow response to intravenous iron injections and partial correction of the anemia. To date, 40 different Matriptase-2 mutations have been reported, affecting all the functional domains of the large ectodomain of the protein. In vitro experiments on transfected cells suggest that Matriptase-2 cleaves Hemojuvelin, a major regulator of hepcidin expression and that this function is altered in this genetic form of anemia. In contrast to the low/undetectable hepcidin levels observed in acquired iron deficiency, in patients with Matriptase-2 deficiency, serum hepcidin is inappropriately high for the low iron status and accounts for the absent/delayed response to oral iron treatment. A challenge for the clinicians and pediatricians is the recognition of the disorder among iron deficiency and other microcytic anemias commonly found in pediatric patients. The current treatment of iron refractory iron deficiency anemia is based on parenteral iron administration; in the future, manipulation of the hepcidin pathway with the aim of suppressing it might become an alternative therapeutic approach.
| S-EPMC3669438 | biostudies-literature
Project description:Iron is essential for life because it is indispensable for several biological reactions, such as oxygen transport, DNA synthesis, and cell proliferation. Over the past few years, our understanding of iron metabolism and its regulation has changed dramatically. New disorders of iron metabolism have emerged, and the role of iron as a cofactor in other disorders has begun to be recognized. The study of genetic conditions such as hemochromatosis and iron-refractory iron deficiency anemia (IRIDA) has provided crucial insights into the molecular mechanisms controlling iron homeostasis. In the future, these advances may be exploited to improve treatment of both genetic and acquired iron disorders. IRIDA is caused by mutations in TMPRSS6, the gene encoding matriptase-2, which downregulates hepcidin expression under conditions of iron deficiency. The typical features of this disorder are hypochromic, microcytic anemia with a very low mean corpuscular volume of erythrocytes, low transferrin saturation, no (or inadequate) response to oral iron, and only a partial response to parenteral iron. In contrast to classic iron deficiency anemia, serum ferritin levels are usually low-normal, and serum or urinary hepcidin levels are inappropriately high for the degree of anemia. Although the number of cases reported thus far in the literature does not exceed 100, this disorder is considered the most common of the "atypical" microcytic anemias. The aim of this review is to share the current knowledge on IRIDA and increase awareness in this field.
| S-EPMC4439901 | biostudies-literature
Project description:TMPRSS6 variants that affect protein function result in impaired matriptase-2 function and consequently uninhibited hepcidin production, leading to iron refractory iron deficiency anemia (IRIDA). This disease is characterized by microcytic, hypochromic anemia and serum hepcidin values that are inappropriately high for body iron levels. Much is still unknown about its pathophysiology, genotype-phenotype correlation, and optimal clinical management. We describe 14 different TMPRSS6 variants, of which 9 are novel, in 21 phenotypically affected IRIDA patients from 20 families living in the Netherlands; 16 out of 21 patients were female. In 7 out of 21 cases DNA sequencing and multiplex ligation dependent probe amplification demonstrated only heterozygous TMPRSS6 variants. The age at presentation, disease severity, and response to iron supplementation were highly variable, even for patients and relatives with similar TMPRSS6 genotypes. Mono-allelic IRIDA patients had a milder phenotype with respect to hemoglobin and MCV and presented significantly later in life with anemia than bi-allelic patients. Transferrin saturation (TSAT)/hepcidin ratios were lower in IRIDA probands than in healthy relatives. Most patients required parenteral iron. Genotype alone was not predictive for the response to oral iron. We conclude that IRIDA is a genotypically and phenotypically heterogeneous disease. The high proportion of female patients and the discrepancy between phenotypes of probands and relatives with the same genotype, suggest a complex interplay between genetic and acquired factors in the pathogenesis of IRIDA. In the absence of inflammation, the TSAT/hepcidin ratio is a promising diagnostic tool, even after iron supplementation has been given. Am. J. Hematol. 91:E482-E490, 2016. © 2016 Wiley Periodicals, Inc.
| S-EPMC6586001 | biostudies-literature
Project description:Iron deficiency is usually attributed to chronic blood loss or inadequate dietary intake. Here, we show that iron deficiency anemia refractory to oral iron therapy can be caused by germline mutations in TMPRSS6, which encodes a type II transmembrane serine protease produced by the liver that regulates the expression of the systemic iron regulatory hormone hepcidin. These findings demonstrate that TMPRSS6 is essential for normal systemic iron homeostasis in humans.
| S-EPMC3104019 | biostudies-literature
Project description:Pathogenic TMPRSS6 variants impairing matriptase-2 function result in inappropriately high hepcidin levels relative to body iron status, leading to iron refractory iron deficiency anemia (IRIDA). As diagnosing IRIDA can be challenging due to its genotypical and phenotypical heterogeneity, we assessed the transferrin saturation (TSAT)/hepcidin ratio to distinguish IRIDA from multi-causal iron deficiency anemia (IDA). We included 20 IRIDA patients from a registry for rare inherited iron disorders and then enrolled 39 controls with IDA due to other causes. Plasma hepcidin-25 levels were measured by standardized isotope dilution mass spectrometry. IDA controls had not received iron therapy in the last 3 months and C-reactive protein levels were <10.0 mg/L. IRIDA patients had significantly lower TSAT/hepcidin ratios compared to IDA controls, median 0.6%/nM (interquartile range, IQR, 0.4-1.1%/nM) and 16.7%/nM (IQR, 12.0-24.0%/nM), respectively. The area under the curve for the TSAT/hepcidin ratio was 1.000 with 100% sensitivity and specificity (95% confidence intervals 84-100% and 91-100%, respectively) at an optimal cut-off point of 5.6%/nM. The TSAT/hepcidin ratio shows excellent performance in discriminating IRIDA from TMPRSS6-unrelated IDA early in the diagnostic work-up of IDA provided that recent iron therapy and moderate-to-severe inflammation are absent. These observations warrant further exploration in a broader IDA population.
| S-EPMC8836508 | biostudies-literature
Project description:Rhabdomyosarcoma (RMS) is a mesenchymal malignancy phenocopying muscle and is among the leading causes of death from childhood cancer. Metastatic alveolar rhabdomyosarcoma is the most aggressive subtype with an 8% 5-yr disease-free survival rate when a chromosomal fusion is present and a 29% 5-yr disease-free survival rate when negative for a fusion event. The underlying biology of PAX-fusion-negative alveolar rhabdomyosarcoma remains largely unexplored and is exceedingly rare in Li-Fraumeni syndrome patients. Here, we present the case of an 11-yr-old male with fusion-negative alveolar rhabdomyosarcoma studied at end of life with a comprehensive functional genomics characterization, resulting in identification of potential therapeutic targets for broader investigation.
| S-EPMC7903883 | biostudies-literature
Project description:Iron-refractory iron-deficiency anemia (IRIDA) is an autosomal recessive disorder caused by mutations in TMPRSS6. Patients have hypochromic microcytic anemia refractory to oral iron and are only partially responsive to parenteral iron administration. We report a French-Canadian kindred in which 2 siblings presented in early childhood with severe microcytic anemia, hypoferremia, and hyperferritinemia. Both children have been successfully treated solely with low-dose oral iron since diagnosis. Clinical and biological presentation did not fit any previously described genetic iron-deficiency anemia. Whole exome sequencing identified in both patients compound heterozygous mutations of TMPRSS6 leading to p.G442R and p.E522K, 2 mutations previously reported to cause classic IRIDA, and no additional mutations in known iron-regulatory genes. Thus, the phenotype associated with the unique combination of mutations uncovered in both patients expands the spectrum of disease associated with TMPRSS6 mutations to include iron deficiency anemia that is accompanied by hyperferritinemia at initial presentation and is responsive to continued oral iron therapy. Our results have implications for genetic testing in early childhood iron deficiency anemia. Importantly, they emphasize that whole exome sequencing can be used as a diagnostic tool and greatly facilitate the elucidation of the genetic basis of unusual clinical presentations, including hypomorphic mutations or compound heterozygosity leading to different phenotypes in known Mendelian diseases.
| S-EPMC3675830 | biostudies-literature
Project description:ObjectivePrimary hyperparathyroidism secondary to an ectopic parathyroid adenoma is rare among children and adolescents.MethodsWe describe the case of an 11-year-old girl with incidentally diagnosed primary hyperparathyroidism secondary to an intrathymic parathyroid adenoma and performed a review of the related literature.Results99mTechnetium sestamibi single-photon emission computerized tomography/computed tomography and 4-dimensional computed tomography confirmed the ectopic location of the adenoma. The patient underwent thoracoscopic thymectomy and remained normocalcemic with elevated parathyroid hormone showing a downward trend. Parathyroid hormone normalized 18 months after successful parathyroidectomy.ConclusionWe review the case of a rare mediastinal parathyroid adenoma in a pediatric patient and summarize the epidemiologic profile, diagnosis, and management of similar pediatric cases.
| S-EPMC8074671 | biostudies-literature
Project description:Abstract Backgrounds Craniosynostosis syndrome has a variety of causes, one of which is an autosomal dominant disorder associated with FGFR1 or FGFR2 gene mutation known as Pfeiffer syndrome (PS; OMIM 101600). It is known that PS is clinically diagnosed, not genetic judgment. PS is divided into three subtypes depending on severity of specific phenotypes. Patients with PS type 1 are broad thumbs and great toes, brachydactyly or syndactyly. They have widely spaced eyes, midface hypoplasia and dental abnormalities but short stature is not typical phenotype of PS. We report the patient who were clinically diagnosed PS with short stature because of growth hormone deficiency (GHD). Case Report: A 4 years 7 month-old girl presented with a short stature below the 3rd percentile. She was born at 40 weeks of gestation with a birth weight of 2.9 kg. Her perinatal and neonatal histories were unremarkable. Her parents are non-consanguineous and her mother had micro- pituitary adenoma. She has healthy younger brother who aged 9 months old. In physical examination, height was 91.1 cm (-3.92 SDS), weight was 15.5 kg (-1.15 SDS). Wide thumb and great toes on both sides of her are observed. At the time of admission, bone age was advanced, measured 7 years. There were no specific findings other than a decrease in IGF-1 level (108.24 ng/ml) and increase in prolactin level (27.26 ng/ml) on the basic endocrine examination. The growth hormone (GH) induced stimulation test was performed after admission. She underwent GH induced stimulation test with combinations of 2 stimulants to assess GH secretion: levodopa 150 mg and arginine 0.5 g/kg. The peak GH level was 7.41 ng/ml in levodopa test and 5.58 ng/ml after 30 minutes’ response to arginine. She was diagnosed as a partial GHD defined by peak GH between 5 and 10 ng/ml in both test. There were no findings in karyotyping and chromosomal microarray. As a result of targeted panel sequencing of 233 genes related to hereditary short stature, c.2398dupT, a pathogenic variant that had not been previously reported in the FGFR2 gene, was observed in a heterozygous form as the cause of short stature. Subsequently, recombinant human GH has been administered in units of 0.1 per day according to her weight. The height was increased from 93.6 cm (SDS) in 4 years 10 months old to 98 cm in 5 years 2 months. Any side effects or adverse reactions were not observed during the treatment period. Conclusion It is suggested that a growth hormone test be performed for Pfeiffer syndrome patients with short stature. GH may help growth in patients with positive in the test. Presentation: No date and time listed
| S-EPMC9625759 | biostudies-literature
Project description:A 11-year-old girl was referred to the pediatric nephrology services of our hospital for evaluation of vitamin-D-refractory rickets. She was born to second-degree consanguineous parents. On examination, she had wrist widening and bilateral genu varum. She had normal anion gap metabolic acidosis, hypokalemia, and hyperchloremia. The fractional excretion of bicarbonate was 3% and the urine anion gap was positive. She also had hypercalciuria, but no phosphaturia, glucosuria or aminoaciduria. In view of a family history of an elder sister having rigidity with cognitive and speech impairment, an ophthalmic evaluation by slit lamp examination was performed in the index case that revealed bilateral Kayser-Fleischer rings. Serum ceruloplasmin was low and 24-h urine copper was elevated in the index case. Whole exome sequencing unveiled a novel pathogenic variant in exon 2 of the ATP7B gene (chr13: c.470del; Depth: 142x) (homozygous) that resulted in a frameshift and premature truncation of the protein, 15 amino acids downstream to codon 157 (p. Cys157LeufsTer15; NM_000053.4) confirming Wilson disease. There were no mutations in the ATP6V0A4, ATP6V1B1, SLC4A1, FOXI1, WDR72 genes or other genes that are known to cause distal RTA. Therapy with D-penicillamine and zinc supplements was initiated. A low dose of 2.5 mEq/kg/day of potassium citrate supplementation normalized the serum bicarbonate levels. This case was notable for the absence of hepatic or neurological involvement at admission. Wilson disease is well known to cause proximal renal tubular acidosis and Fanconi syndrome, with relatively lesser involvement of the distal renal tubules in the literature. However, isolated distal renal tubular involvement as presenting manifestation of Wilson disease (without hepatic or neurological involvement) is rare and can lead to diagnostic confusion.
| S-EPMC10982190 | biostudies-literature