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Thiamine-responsive megaloblastic anaemia (TRMA) is a rare autosomal recessive disorder characterised by the clinical triad of megaloblastic anaemia, sensorineural hearing loss and diabetes mellitus (DM) in young patients. We present a case of a young man with type 1 DM who presented with pancytopenia of unclear aetiology, initially attributed to a COVID-19 infection. After obtaining a bone marrow biopsy and pursuing genetic testing, two pathogenic variants of the SLC19A2 gene consistent with TRMA were discovered in this patient. Treatment with 100 mg of thiamine oral supplementation daily led to the complete resolution of his pancytopenia. It is important to consider a genetic cause of pancytopenia in a young person. Early recognition and diagnosis of TRMA can be life-altering given early treatment can reduce insulin requirements and resolve anaemia., Competing Interests: Competing interests: None declared., (© BMJ Publishing Group Limited 2024. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: Imerslund-Gräsbeck syndrome (IGS) is an autosomal recessive disorder characterized by selective vitamin B12 malabsorption, resulting in vitamin B12 deficiency and impaired reabsorption of proximal tubular proteins.This case highlights a previously unidentified compound heterozygous variant in the Amnionless (AMN) gene that causes IGS syndrome and underscores the importance of long-term oral vitamin B12 replacement therapy in managing the condition., Case Presentation: In this retrospective analysis, we present the clinical data of a 3-year and 6-month-old female child diagnosed with IGS at Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, China, in November 2018. The child was admitted to the hospital due to a history of anemia persisting for over a month. There was no previous significant medical history. The admission examination revealed megaloblastic anemia with proteinuria. Serum vitamin B12 levels were decreased, while folic acid and renal function were normal. The patient was diagnosed with megaloblastic anemia and started long-term oral vitamin B12 replacement therapy. Throughout the follow-up period, blood tests consistently showed normal results, while proteinuria persisted. In November 2019, the child and her parents underwent whole exome sequencing analysis, which revealed a novel compound heterozygous variant in the AMN gene: c.162 + 1G > A and c.922 C > T (p.Q308X) in the child, c.162 + 1G > A in the father, and c.922 C > T (p.Q308X) in the mother. Therefore, this child was further diagnosed with IGS., Conclusions: In this case, whole exome sequencing proves to be highly practical in daily healthcare for diagnosing and refining rare or ultra-rare diseases with ambiguous phenotypes or genetic diversity. It is also valuable for prognostic evaluation and personalized management. Additionally, the oral vitamin B12 treatment demonstrated positive clinical effects for the child, offering a new option for patients unable to undergo intramuscular vitamin B12 replacement therapy., (© 2024. The Author(s).)

Background: Vitamin B12 is primarily transported from plasma to cells by Transcobalamin. Deficiency of Transcobalamin is a rare autosomal recessive disorder that results in unavailability of cobalamin in cells and accumulation of homocysteine and methylmalonic acid., Case Report: We report a case of a 2-year-old male child with persistent pancytopenia, recurrent infections, and megaloblastic anemia. Next-generation sequencing identified a novel variant in exon 8 of TCN2 gene. Substantial improvement has been observed following administration of high doses of parenteral methylcobalamin., Conclusion: In patients with unresolved pancytopenia and megaloblastic anemia, Transcobalamin deficiency should be investigated and treated promptly to prevent any irreversible and harmful outcome., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Vitamin B12 and folate deficiency are reversible causes of megaloblastic anemia . Strict vegetarians are at risk of megaloblastic anemia due to low cobalamin in their diet . Knuckle hyperpigmentation in patients with megaloblastic anemia is due to excess melanin synthesis in skin. Here we present a case of a young vegetarian male with megaloblastic anemia with knuckle hyperpigmentation managed successfully with intravenous followed by oral vitamin b12 and folate supplementation., Competing Interests: Declaration of conflicting interestsThe authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Background: Individuals with thiamine-responsive megaloblastic anemia (TRMA) mainly manifest macrocytic anemia, sensorineural deafness, ocular complications, and nonautoimmune diabetes. Macrocytic anemia and diabetes may be responsive to high-dosage thiamine treatment, in contrast to sensorineural deafness. Little is known about the efficacy of thiamine treatment on ocular manifestations., Cases Presentation: Our objective is to report data from four Italian TRMA patients: in Cases 1, 2 and 3, the diagnosis of TRMA was made at 9, 14 and 27 months. In 3 out of 4 subjects, thiamine therapy allowed both normalization of hyperglycemia, with consequent insulin suspension, and macrocytic anemia. In all Cases, thiamine therapy did not resolve the clinical manifestation of deafness. In Cases 2 and 3, follow-up showed no blindness, unlike Case 4, in which treatment was started for megaloblastic anemia at age 7 but was increased to high doses only at age 25, when the genetic diagnosis of TRMA was performed., Conclusions: Early institution of high-dose thiamine supplementation seems to prevent the development of retinal changes and optic atrophy in TRMA patients. The spectrum of clinical manifestations is broad, and it is important to describe known Cases to gain a better understanding of this rare disease., (© 2023. The Author(s).)

We report a 26-year-old girl who was diagnosed with diabetes mellitus in her childhood and was treated with insulin. With a history of visual disturbances during her childhood and anaemia, which was partially evaluated; the possibility of syndromic diabetes was considered. Genetic analysis was done and revealed a mutation in the SLC19A2 gene, confirming the diagnosis of thiamine-responsive megaloblastic anaemia. She was supplemented with thiamine, which dramatically improved her haemoglobin levels and glucose control. However, her vision could not be salvaged as the rod-cone dystrophy is a permanent damage.

Background: Anemia-causing fever has been described in patients with megaloblastic anemia. Although the exact mechanism of this is unknown, high-grade fever is relatively less reported., Materials and Methods: This prospective observational study included all new cases of megaloblastic anemia presenting with febrile illness (>101°F) during a 3-year period. Patients with existing anemia, comorbidities, and other causes of macrocytosis were excluded. A detailed evaluation for megaloblastic anemia and workup for excluding tropical infections was done. The patients were treated with parenteral vitamin B12, folic acid, and other hematinics., Results: Around 24 cases of megaloblastic anemia presenting with high-grade fever were included, with 14 (58.3%) males, mean duration of fever 7.7 days (4-18 days), and 09 (37.5%) having temperature >103°F. The mean hemoglobin (Hb) was 8.15 g/dL (3.7-11.1 g/dL), the mean corpuscular volume (MCV) was 111 ± 7.8 fL, 18 (75%) had unconjugated hyperbilirubinemia, the mean lactate dehydrogenase (LDH) was 814 ± 24 IU/L, and 21 (87.5%) had low B12 or folate levels. Most showed good therapeutic response to B12 or folic acid with defervescence in 1-5 days (mean 2.6 days) and improvement in lab parameters in 1 week. The study population was divided into those with temperature ≥103°F, and temperature <103°F it was seen that there was a significant association (p < 0.05) with leucocyte count of ≤3000/cumm, and MCV ≥110 fL, in patients with temperature ≥103°F Conclusion: Megaloblastic anemia should be considered in the differentials of a patient presenting with a febrile illness with no clinical localization and a negative initial fever workup. Early identification and prompt therapy of this easily treatable disorder are very essential., (© Journal of the Association of Physicians of India 2011.)

Vitamin B12, or cobalamin, belongs to the group of water-soluble vitamins and is ingested through food of animal origin such as eggs, milk, red meat and poultry, fish, and shellfish. Its clinical indication is the treatment of hypovitaminosis B12 administered orally or intramuscularly in the form of hydroxocobalamin. Hypovitaminosis B12 is mainly caused by deficient dietary intake (individuals with malnutrition, vegetarians or vegans, older adults, pregnant people, individuals with alcohol use disorder); when intestinal absorption is reduced (atrophic gastritis, malabsorption syndrome, gastrointestinal surgery); and for causes associated with the intake of drugs (antacids, metformin). Hypervitaminosis B12 has been associated with renal failure; liver diseases such as cirrhosis and acute-phase hepatitis; alcohol use disorder with or without liver involvement; solid tumors of the lung, liver, esophagus, pancreas, and colorectum; and in hematological malignancies such as leukemia and bone marrow dysplasia., (Copyright © 2022 Elsevier España, S.L.U. and Sociedad Española de Medicina Interna (SEMI). All rights reserved.)

Background: There is limited literature in children on efficacy of different routes of vitamin B12 administration for vitamin B12 deficiency macrocytic-megaloblastic anemia., Objective: To compare parenteral with oral vitamin B12 therapy in children with macrocytic-megaloblastic anemia., Study Design: Single-center, open-label randomized controlled trial., Participant: 80 children aged 2 month-18 year with clinical and laboratory features of nutritional macrocytic anemia., Intervention: All children received an initial single parenteral dose of 1000 µg vitamin B12 followed by randomization to either parenteral or oral vitamin B12 for subsequent doses. Group A was given 1000 µg intramuscular (IM) vitamin B12 (3 doses on alternate days for those aged <10 year, five doses for age >10 year), followed by monthly 1000 µg IM for the subsequent two doses. Group B was given daily oral vitamin B12 1500 µg (500 µg in <2 years age) for three months. Folic acid and iron supple-mentation, and relevant dietary advice were given to both groups in a similar fashion., Outcome: Improvement in serum vitamin B12 levels and total hemoglobin was compared three months post-treatment., Result: The median(IQR) increase in serum vitamin B12 level was significantly higher in group A [600 (389,775) vs 399 (313, 606) pg/mL; P= 0.016]. The median (IQR) rise of hemoglobin was also more in group A [2.7 (0.4,4.6) vs 0.5 (-0.1,1.2) g/dL; P=0.001]., Conclusion: Increase in serum vitamin B12 levels and hemoglobin was better in children with nutritional macrocytic anemia receiving parenteral as compared to oral vitamin B12.

Introduction: In infants, vitamin B12 deficiency is mainly due to nutritional deficiencies related to maternal deficit. Most cases of maternal deficiencies are associated with vegetarian diets. Pernicious anemia is an au toimmune disease that affects the absorption of this vitamin. Although it is less common than nutri tional deficiency, is also an important cause of maternal deficiency., Objective: to report a case of an infant with vitB12 deficiency, secondary to pernicious anemia in his mother, and to review the most important aspects of this disease in childhood., Clinical Case: Nine months-old male infant, without pathological perinatal history, exclusively breastfed, with persistent rejection of solid food from 6 months of age. One month before hospitalization, he progressively presented hyporesponsiveness, with fluctuating state of alertness, regression of motor development milestones, and vomiting. The blood count showed macrocytic anemia and neutropenia. Vitamin B12 deficiency was confirmed in the patient. He received treatment with intramuscular vitamin B12 with good clinical and laboratory response. Maternal B12 deficiency was confirmed as the cause of the infant's deficiency. Since the mother reported no dietary restrictions, anti-intrinsic factor and anti-parietal cell antibodies were measured, leading to the diagnosis of pernicious anemia., Conclusions: Early recognition is essential to prevent the development of potentially irreversible neurological damage. Maternal pernicious ane mia should be considered in children with megaloblastic anemia, especially in those whose mothers do not follow vegetarian diets.

Vitamin B12 deficiency in children can cause megaloblastic anemia, poor growth, and increased chances of infections. It is an important reversible cause of bone marrow suppression which at the time of presentation can mimic hematological malignancy. Therefore, it should be considered as a differential diagnosis in cases suspected of acute leukemia. We report a case of 14 months old child who had atypical presentation of vitamin B12 deficiency. He had chronic fever, decreased feeding and increased paleness for one year. Pancytopenia with severe anemia was present along with 19% reactive/atypical cells in peripheral blood smear suggesting acute leukemia. However, bone marrow aspiration and biopsy showed features of megaloblastic anemia. Vitamin B12 level measured was very low and treatment with cyanocobalamin caused drastic improvement in the child's condition.

Introduction: Imerslund-Gräsbeck syndrome (IGS) is a rare autosomal-recessive disorder characterized by selective vitamin B12 malabsorption, megaloblastic anemia, and proteinuria. The precise incidence of this disorder is unknown in the Middle East and Arab countries. The disease is caused by a homozygous variant in either AMN or CUBN genes. In addition, some compound heterozygous variants are reported., Methods: Clinical and laboratory data of patients diagnosed with IGS in Oman were retrospectively collected. Mutation analysis for all genes involved in vitamin B12/folic acid metabolism and megaloblastic anemia was conducted using next-generation sequencing (NGS)., Results: Three siblings (2 girls and a boy) have been diagnosed with the condition. They exhibit a phenotypic variability with different age of presentation and different spectrum of disease. All patients harbor a novel biallelic frameshift mutation in exon 11 of AMN gene (p.Pro409Glyfs*), which was not reported previously in the literature. Both parents are heterozygotes for the same variant. All patients responded well to vitamin B12 parenteral therapy, but proteinuria persisted., Conclusion: In communities with high incidence of consanguinity, cases of early-onset vitamin B12 deficiency should be thoroughly investigated to explore the possibility of Imerslund-Gräsbeck syndrome and other vitamin B12-related hereditary disorders. Further local and regional studies are highly recommended., (© 2021 John Wiley & Sons Ltd.)

Background: In ineffective erythropoiesis, hepcidin synthesis is suppressed by erythroid regulators, namely erythroferrone and growth differentiation factor-15. For the first time, the hypothesis that iron overload in megaloblastic anemia may be related to ineffective erythropoiesis is explored by describing the kinetics of hepcidin, erythroferrone, and growth differentiation factor-15 levels in a patient diagnosed with megaloblastic anemia associated with iron overload., Case Presentation: An 81-year-old Caucasian male was admitted for fatigue. He had type-2 diabetes previously treated with metformin, ischemic cardiac insufficiency, and stage-3 chronic kidney disease. Vitiligo was observed on both hands. Biological tests revealed normocytic non-regenerative anemia associated with hemolysis, thrombocytopenia, and elevated sideremia, ferritin, and transferrin saturation levels. Megaloblastic anemia was confirmed with undetectable blood vitamin B12 and typical cytological findings like hyper-segmented neutrophils in blood and megaloblasts in bone marrow. The patient received vitamin B12 supplementation. At 3 months, biological parameters reached normal values. Hepcidin kinetics from diagnosis to 3 months inversely correlated with those of erythroferrone and growth differentiation factor-15., Conclusions: This case suggests that iron-overload mechanisms of dyserythropoietic anemias may apply to megaloblastic anemias., (© 2021. The Author(s).)

Background and Aims: Thiamine-responsive megaloblastic anemia (TRMA), caused by SLC19A2 loss-of-function variants, is characterized by the triad of megaloblastic anemia, progressive sensorineural deafness, and non-type 1 diabetes mellitus. Here, we present the case of a Chinese infant with two novel variants segregating in compound heterozygous form in SLC19A2 and reviewed genotype-phenotype associations (GPAs) in patients with TRMA., Materials and Methods: Whole-exome sequencing was performed to establish a genetic diagnosis. The clinical manifestations and genetic variants were collected by performing a literature review. The bioinformatics software SIFT, PolyPhen2, and Mutation Taster was applied to predict variant effects and analyze GPAs., Results: Two novel variants segregating in compound heterozygous form in SLC19A2 (NM&#95;006996.2: exon2:c.336&#95;363del:p.W112fs; exon2:c.358G>T:p.G120X) was identified. Thiamine supplementation corrected anemia and diabetes mellitus but did not improve the hearing defect. In the literature, 183 patients with TRMA with 74 variants in SLC19A2 have been reported, with high incidence in the Middle East, South Asia, and the northern Mediterranean. Patients with biallelic premature termination codon variants presented with more severe phenotypes, and truncating sites on extracellular domains was a protective factor for the hemoglobin level at diagnosis., Conclusion: Two novel compound heterozygous variants (NM&#95;006996.2: exon2:c.336&#95;363del:p.W112fs; exon2:c.358G>T:p.G120X) were identified, and GPAs in TRMA indicated the predictability of clinical manifestations., (Copyright © 2021 The Authors. Published by Elsevier B.V. All rights reserved.)

Purpose: To report on 5-year multimodal imaging of ocular findings in a patient with thiamine-responsive megaloblastic anemia., Methods: Observational case report., Results: A 20-year-old-man with a history of thiamine-responsive megaloblastic anemia demonstrated a symmetric bull's eye maculopathy. Spectral domain optical coherence tomography revealed disruption of the parafoveal ellipsoid zone, fundus autofluorescence demonstrated foveal hypoautofluorescence, and full-field electroretinogram testing revealed a decreased photopic and scotopic response consistent with cone-rod dystrophy. His best-corrected visual acuity remained stable over 5 years at 20/50 in the right eye and 20/40 in the left eye, and visual field testing remained stable over time., Conclusion: Ocular manifestations in thiamine-responsive megaloblastic anemia are uncommon and variable. In this case, multimodal imaging and electroretinogram findings are consistent with cone-rod degeneration. The patient is taking daily thiamine supplementation, and visual acuity, funduscopic examination, spectral domain optical coherence tomography, and autofluorescence remained stable over a 5-year period.

A 62-year-old Japanese woman developed numbness of the extremities and megaloblastic anemia. She had undergone total abdominal hysterectomy, whole-pelvis radiation therapy and chemotherapy for gynecological cancer 10 years before. Chronic abdominal pain, diarrhea and intermittent small-bowel obstruction had afflicted her for a long time. We diagnosed her with vitamin B12 deficiency anemia and polyneuropathy due to chronic radiation enteritis causing malabsorption. Vitamin B12 injections improved her numbness and anemia. The early diagnosis and treatment of deficiency of vitamin B12 are important. Physicians should regularly measure vitamin B12 levels and supplement vitamin B12 as needed in patients with chronic radiation enteritis.

Background: Thiamine-responsive megaloblastic anemia (TRMA) is a rare autosomal recessive inherited disease characterized by the clinical triad of megaloblastic anemia, sensorineural deafness, and diabetes mellitus. To date, only 100 cases of TRMA have been reported in the world., Case Presentation: Here, we describe a six-year-old boy with diabetes mellitus, anemia, and deafness. Additionally, he presented with thrombocytopenia, leukopenia, horizontal nystagmus, hepatomegaly, short stature, ventricular premature beat (VPB), and cerebral infarction. DNA sequencing revealed a novel compound heterozygous mutation in the SLC19A2 gene: (1) a duplication c.405dupA, p.Ala136Serfs*3 (heterozygous) and (2) a nucleotide deletion c.903delG p.Trp301Cysfs*13 (heterozygous). The patient was diagnosed with a typical TRMA., Conclusion: Novel mutations in the SLC19A2 gene have been identified, expanding the mutation spectrum of the SLC19A2 gene. For the first time, VPB and cerebral infarction have been identified in patients with TRMA syndrome, providing a new understanding of the phenotype.

A female child with deafness was diagnosed to have neonatal diabetes mellitus at the age of 6 months, on routine evaluation prior to cochlear implant surgery. She presented to us at 11 months of age with diabetic ketoacidosis due to an intercurrent febrile illness. Her haematological parameters showed megaloblastic anaemia and thrombocytopenia. Therefore a possibility of Thiamine Responsive Megaloblastic Anaemia (TRMA) syndrome was considered. She was empirically treated with parenteral thiamine hydrochloride (Hcl). Subsequently, due to the unavailability of pharmacological preparation of oral thiamine Hcl in a recommended dose she was treated with benfotiamine. She had a sustained improvement in all her haematological parameters on oral benfotiamine. The insulin requirement progressively reduced and she is currently in remission for last 2 years. The genetic analysis confirmed the diagnosis of TRMA syndrome. Thus benfotiamine can be considered a new treatment option in management of TRMA syndrome., Competing Interests: Competing interests: None declared., (© BMJ Publishing Group Limited 2019. No commercial re-use. See rights and permissions. Published by BMJ.)

Normal red blood cells maturation depends on many different hematological factors, including vitamin (vit.) B12. Megaloblastic anemias are basically caused by vit. B12 deficiency. In childhood the deficiency of this vitamin is extremely rare. The article captures findings of observation of the patient with rare form congenital vit. B12 deficiency anemia - Imerslund-Gräsbeck syndrome. The disease is characterized with selective intestinal malabsorption of vit. B12 and permanent proteinuria, without sings of kidney disease. The diagnosis was confirmed by our team in early childhood and based on the history, clinical and paraclinical data. After two weeks of specific treatment with vit. B12 , complete clinical - hematological remission was achieved. Treatment includes lifelong vit. B12 injections once per month. Cathamnesic observation for 18 months revealed that the patient is in remission, but there was continued macrocytosis of red blood cells and mild proteinuria. The presented case is interesting as a rare case of megaloblastic anemia caused by vit. B12 deficiency in childhood. Such patients often treated under different diagnosis. In such cases early diagnosis, treatment and prevention are crucial for the good prognosis.

A combination of anaemia and knuckle pigmentation should always raise concern for megaloblastic anaemia. As the terminal ileum is the site of vitamin B 12 absorption and also the commonest site of abdominal tuberculosis, a clinical triad of prolonged fever, knuckle pigmentation and right lower quadrant abdominal tenderness should suggest ileocaecal tuberculosis in endemic areas.

Background: Efficacy of PO cobalamin (Cbl) supplementation in dogs with hereditary Cbl malabsorption (Imerslund-Gräsbeck syndrome, IGS) is unknown., Objectives: To evaluate PO Cbl supplementation in Beagles with IGS previously treated parenterally. We hypothesized that 1 mg cyano-Cbl daily PO would maintain clinical and metabolic remission., Animals: Three client-owned Beagles with IGS and 48 healthy control dogs., Methods: Prospective study. Daily PO cyanocobalamin (cyano-Cbl; 1 mg) supplementation was monitored for 13 (2 dogs) and 8 months (1 dog). Health status was assessed by owner observations. Methylmalonic acid (MMA)-to-creatinine concentrations were measured using an ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-TMS) method on urine samples collected monthly. Concurrent measurements of serum MMA concentration (n = 7; UPLC-TMS) were available for 1 dog., Results: All dogs remained in excellent health during PO supplementation. Urine MMA remained consistently low in 2 dogs (median, 2.5 mmol/mol creatinine; range, 1.2-9; healthy dogs [n = 30], median, 2.9 mmol/mol creatinine; range, 1.3-76.5). Urine MMA ranged from 38.9-84.9 mmol/mol creatinine during the first 6 months in 1 dog already known to excrete comparable amounts when supplemented parenterally. Brief antibiotic treatment for an unrelated condition after 6 months resulted in low urine MMA (median, 2.8 mmol/mol creatinine; range, 1.9-4.8) for the next 7 months. All concurrent serum MMA concentrations (median, 651 nmol/L; range, 399-919) before and after month 6 were within the established reference interval (393-1476 nmol/L; n = 48)., Conclusions and Clinical Importance: One milligram of cyano-Cbl daily PO appears efficacious for maintaining normal clinical status and normal cellular markers of Cbl metabolism in Beagles with IGS., (© 2018 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals, Inc. on behalf of the American College of Veterinary Internal Medicine.)

We describe 2 children with cobalamin G disease, a disorder of vitamin B 12 metabolism with normal serum B 12 levels. They presented with megaloblastic anemia progressing rapidly to severe thrombotic microangiopathy. In infants presenting with acute thrombotic microangiopathy, cobalamin disorders should be considered early as diagnosis and targeted treatment can be lifesaving., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Thiamine-responsive megaloblastic anemia (TRMA) syndrome is an autosomal recessive inherited disorder characterised by a triad of megaloblastic anemia, diabetes mellitus, and sensorineural deafness. We report a case of 2-year-old girl whose anemia improved following administration of thiamine. She came with the history of persistent anaemia for the last one year. Anaemia was not responding to iron, vitamin B12, and folate replacement therapy. The bone marrow aspiration revealed hypercellular marrow with megaloblastic changes and more than 15% ring sideroblasts. The hearing assessment revealed sensorineural hearing loss. Blood sugar random and HBA1c was raised. Final diagnosis of TRMA was made. She was started on thiamine 100 mg OD, with normal routine balanced diet. She responded very well to thiamine. Her haemoglobin improved and blood sugar fasting came down in normal range. This case report sensitises the early diagnosis, and treatment with thiamine in children presenting with anemia, diabetes and deafness.

Thiamine-responsive megaloblastic anaemia (TRMA) is a syndrome associated with megaloblastic anaemia, diabetes mellitus and sensorineural deafness, due to mutations in the SLC19A2 gene, which codes for a thiamine carrier protein. Oral thiamine supplementation is the main treatment. We report the case of a 25-year-old woman known for TRMA, who presented with pancytopenia (haemoglobin 7.6 g/dL, leucocytes 2.9×10 9 /L, thrombocytes 6×10 9 /L) revealed by dyspnoea. Investigations excluded coagulopathy, a recent viral infection, vitamin and iron deficiencies, and a malignant process. We later found out that thiamine treatment had been discontinued 5 weeks before, due to prescription error. Parenteral thiamine administration resulted in the recovery of haematopoiesis within 3 weeks. Pancytopenia is uncommon in patients with TRMA. Pre-existing medullary impairment caused by the patient's daily antipsychotic medications or the natural course of the syndrome may explain the severity of the laboratory findings in our patient., Competing Interests: Competing interests: None declared., (© BMJ Publishing Group Ltd (unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.)

Aims/hypothesis: Diabetes is one of the cardinal features of thiamine-responsive megaloblastic anaemia (TRMA) syndrome. Current knowledge of this rare monogenic diabetes subtype is limited. We investigated the genotype, phenotype and response to thiamine (vitamin B 1 ) in a cohort of individuals with TRMA-related diabetes., Methods: We studied 32 individuals with biallelic SLC19A2 mutations identified by Sanger or next generation sequencing. Clinical details were collected through a follow-up questionnaire., Results: We identified 24 different mutations, of which nine are novel. The onset of the first TRMA symptom ranged from birth to 4 years (median 6 months [interquartile range, IQR 3-24]) and median age at diabetes onset was 10 months (IQR 5-27). At presentation, three individuals had isolated diabetes and 12 had asymptomatic hyperglycaemia. Follow-up data was available for 15 individuals treated with thiamine for a median 4.7 years (IQR 3-10). Four patients were able to stop insulin and seven achieved better glycaemic control on lower insulin doses. These 11 patients were significantly younger at diabetes diagnosis (p = 0.042), at genetic testing (p = 0.01) and when starting thiamine (p = 0.007) compared with the rest of the cohort. All patients treated with thiamine became transfusion-independent and adolescents achieved normal puberty. There were no additional benefits of thiamine doses >150 mg/day and no reported side effects up to 300 mg/day., Conclusions/interpretation: In TRMA syndrome, diabetes can be asymptomatic and present before the appearance of other features. Prompt recognition is essential as early treatment with thiamine can result in improved glycaemic control, with some individuals becoming insulin-independent., Data Availability: SLC19A2 mutation details have been deposited in the Decipher database ( https://decipher.sanger.ac.uk/ ).

A sustained increase of cancer antigen 15-3 serum levels was found in a 54-year-old woman treated 2 years ago for early stage breast cancer, without any evidence of cancer recurrence. The patient thereafter developed severe megaloblastic anemia secondary to vitamin B12 deficiency. Supplementation with B12 to reverse the anemia led to the normalization of the cancer antigen 15-3 serum levels. As such, with the limited understanding of molecular biology, the integrative approach of clinical history, physical examination, and diagnostic imaging remain pivotal in the management of cancer patients.

Background: Prospective studies on maintenance treatment for Beagles with hereditary selective cobalamin (Cbl) malabsorption (Imerslund-Gräsbeck syndrome, IGS) are lacking. In our experience, measurement of methylmalonic acid (MMA), a Cbl-dependent metabolite, seems more helpful to monitor Cbl status as compared with serum Cbl concentrations., Objectives: To evaluate a standardized Cbl supplementation scheme in Beagles with IGS. We hypothesized that a single parenteral dose of 1 mg hydroxocobalamin (OH-Cbl) would maintain clinical and metabolic remission for up to 2 months., Animals: Six client-owned juvenile Beagles with genetically confirmed IGS and 28 healthy control dogs., Methods: Prospective study. Monthly IM OH-Cbl (1 mg) supplementation was done over a median of 9 months (range, 6-13) in 6 dogs, followed by bimonthly (every 2 months) injections in 5 dogs over a median of 6 months (range, 3-10). Health status was assessed by routine clinical examinations at injection time points and owner observations. Voided urine samples were collected immediately before OH-Cbl injections for measurement of MMA-to-creatinine concentrations using a gas-liquid chromatography-tandem mass spectrometry (GC-MS) method., Results: All dogs were clinically healthy while receiving monthly and bimonthly OH-Cbl supplementation. Urinary MMA results in healthy dogs ranged from 1.3 to 76.5 mmol/mol creatinine (median, 2.9). Median urinary MMA concentrations did not differ between dogs with IGS receiving monthly (n = 49; 5.3 mmol/mol creatinine; range, 2.3-50.4) and bimonthly (n = 31; 5.3 mmol/mol creatinine; range, 1.6-50) injections., Conclusions and Clinical Importance: A maintenance parenteral dose of 1 mg OH-Cbl monthly or bimonthly appears adequate in Beagles with IGS monitored by metabolic testing., (Copyright © 2018 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals, Inc. on behalf of the American College of Veterinary Internal Medicine.)

Argun M, Baykan A, Hatipoğlu N, Akın L, Şahin Y, Narin N, Kurtoğlu S. Arrhythmia in thiamine responsive megaloblastic anemia syndrome. Turk J Pediatr 2018; 60: 348-351. Thiamine responsive megaloblastic anemia syndrome (TRMAS) is a rare, autosomal recessive disorder characterized by megaloblastic anemia, diabetes mellitus, and progressive sensorineural deafness. Mutations in the SLC19A2 gene that codes for thiamine transporter 1 protein cause TRMAS, and more than 30 homozygous mutations have been identified to date. Congenital heart diseases and arrhythmias have been reported in few patients. We present cardiac features of five patients with TRMAS. Five patients had macrocytic anemia, diabetes mellitus, and sensorineural deafness. Two siblings had also optic atrophy. SLC19A2 gene mutation was shown in all patients. Two patients developed supraventricular tachycardia during an episode of diabetic ketoacidosis. Five patients had absent P waves on baseline electrocardiography, and one patient had additional low QRS voltage. None of the patients had structural heart disease. Discontinuation of thiamine treatment appears to trigger supraventricular tachycardia episodes at puberty.

Three siblings with thiamine-responsive megaloblastic anemia (TRMA) with a homozygous c.454delGGCATinsAT mutation in SLC19A2 are described. The index case presented at 14 months' old with severe non-ketotic hyperglycemia, dehydration, seizures and sinovenous thrombosis. She was started on insulin and developed sensorineural hearing loss around 2 years old. Two siblings were found to have the same mutation and were started on thiamine. One sibling developed transient hyperglycemia after several years of thiamine supplementation of 12 mg/kg that resolved with an increased thiamine dose (23 mg/kg). A younger sibling continues to remain diabetes-free on thiamine (24 mg/kg). The clinical course in this family suggests that there is an effect of thiamine on pancreatic beta cell function in patients with TRMA given the resolution of impaired fasting glucose with increasing thiamine dose in one sibling and the lack of diabetes to date in the siblings that were treated early with thiamine.

Hepatitis B virus (HBV) typically causes chronic hepatitis, cirrhosis, and hepatocellular carcinoma. It is associated with a variety of extrahepatic complications. We herein, present a rare extrahepatic complication of HBV infection. A 32-year man presented with melena, bleeding from gums and fever. Peripheral blood examination revealed anemia, macrocytosis and severe thrombocytopenia. His hepatitis B surface antigen (HBsAg) was positive but deoxyribonucleic acid (HBV DNA) by polymerase chain reaction (PCR) was negative. Other hepatitis, human immune deficiency virus (HIV), dengue, and autoimmune serology were negative. Bone marrow examination revealed megaloblastic erythropoiesis. There was mild to moderate reduction of megakaryocytes in bone marrow, which was not compatible with severe peripheral thrombocytopenia. His response to cyanocobalamin and folic acid was remarkable for myeloid cell lines and moderate for erythroid cell lines, but poor to platelet counts. Platelet counts gradually improved to safe limits with eltrombopag, likely reflecting autoimmune pathogenesis for thrombocytopenia. This case report highlights multiple targets of HBV infection with associated multiple pathogenetic mechanisms.

Background: Methylenetetrahydrofolate dehydrogenase (MTHFD1) deficiency has recently been reported to cause a folate-responsive syndrome displaying a phenotype that includes megaloblastic anemia and severe combined immunodeficiency., Objective: To describe our investigative approach to the molecular diagnosis and evaluation of immune dysfunction in a family with MTHFD1 deficiency., Methods: The methods used were exome sequencing and analysis of variants in genes involved in the folate metabolic pathway in a family with 2 affected siblings. Routine laboratory and research data were analyzed to gain an in-depth understanding of innate, humoral, and cell-mediated immune function before and after folinic acid supplementation., Results: Interrogation of exome data for concordant variants between the siblings in the genes involved in folate metabolic pathway identified a heterozygous mutation in exon 3 of the MTHFD1 gene that was shared with their mother. In view of highly suggestive phenotype, we extended our bioinformatics interrogation for structural variants in the MTHFD1 gene by manual evaluation of the exome data for sequence depth coverage of all the exons. A deletion involving exon 13 that was shared with their father was identified. Routine laboratory data showed lymphopenia involving all subsets and poor response to vaccines. In vitro analysis of dendritic cell and lymphocyte function was comparable to that in healthy volunteers. Treatment with folinic acid led to immune reconstitution, enabling discontinuation of all prophylactic therapies., Conclusions: Exome sequencing demonstrated MTHFD1 deficiency as a novel cause of a combined immunodeficiency. Folinic acid was established as precision therapy to reverse the clinical and laboratory phenotype of this primary immunodeficiency., (Copyright © 2016 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.)