Thiamine-Responsive Megaloblastic Anaemia With Hypothyroidism, A Puzzling Association.

Background: Thiamine-responsive megaloblastic anaemia (TRMA) is characterized by the classic trio of diabetes mellitus, sensorineural hearing loss, and megaloblastic anaemia, typically emerging subtly between infancy and adolescence. Administration of high-dose thiamine often yields improvements in anaemia and occasionally in diabetes. Uncommon manifestations include optic atrophy, congenital heart defects, short stature, and stroke. In this specific case, a 5-year-old diagnosed with insulin-dependent diabetes mellitus (IDDM) since the age of one presented with symptoms such as polyuria, fever, and vomiting, revealing an HbA1c of 10.64. Further examinations disclosed compromised hearing and vision. A negative antibody workup and a thyroid profile indicating hypothyroidism prompted additional investigations, including Brainstem Evoked Response Audiometry (BERA) and retinal examination, confirming bilateral sensorineural hearing loss and maculopathy, respectively. A comprehensive blood count unveiled megaloblastic anaemia. Genetic profiling confirmed a homozygous mutation in the SLC19A2 gene, thus diagnosing TRMA. An early diagnosis, coupled with genetic confirmation, enables timely intervention, with patients responding positively to high-dose thiamine. Genetic counselling plays a pivotal role in enlightening families about the disease and its inheritance patterns, fostering awareness and understanding.

Thiamine-Responsive Megaloblastic Anemia-Related Diabetes: Long-Term Clinical Outcomes in 23 Pediatric Patients From the DPV and SWEET Registries.

OBJECTIVES: To describe clinical presentation and long-term outcomes in a large cohort of children diagnosed with thiamine-responsive megaloblastic anemia (TRMA)-related diabetes. METHODS: Data from the Diabetes Patienten Verlaufsdokumentation (DPV) and Better control in Pediatric and Adolescent diabeteS: Working to crEate CEnTers of Reference (SWEET) registries were used to identify cases. Complementary information was collected through a chart review of each case. Descriptive analyses with medians and interquartile ranges and numbers (proportions) were tabulated. RESULTS: We identified 23 cases (52% male) in the 2 registries. Eighteen (78%) had genetic confirmation of TRMA. Median age at diabetes onset was 1.4 (quartiles 0.8 to 3.6) years and median age at initiation of thiamine treatment was 5.9 (2.4 to 12.4) years. At their most recent visit, patients' median age was 14.3 (8.1 to 17.5) years, glycated hemoglobin level was 6.9% (6.1% to 7.9%), insulin dose was 0.9 (0.4 to 1.2) units/kg per day and thiamine dose was 200 (100 to 300) mg/day. Three patients were not treated with insulin or antidiabetic drugs. There was no difference in diabetes outcomes in patients with initiation of thiamine ≤1 year after diabetes onset compared to patients with initiation of thiamine >1 year after diabetes onset. CONCLUSIONS: This is the longest case series of pediatric TRMA-related diabetes reported to date. Diabetes onset often occurs several years before initiation of thiamine supplementation. Early initiation of thiamine (within 1 year of diabetes onset) was not linked to improved diabetes outcome. However, the role of thiamine in pancreatic function needs further assessment. Patients with TRMA-related diabetes maintained good glycemic control even after 9 years (median) of follow up.

LONG-TERM MULTIMODAL IMAGING OF OCULAR FINDINGS ASSOCIATED WITH THIAMINE-RESPONSIVE MEGALOBLASTIC ANEMIA.

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.

Pancytopenia in an adult patient with thiamine-responsive megaloblastic anaemia.

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 2.9×109/L, thrombocytes 6×109/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.

Deficiência de vitamina B12 e fenilcetonúria / Vitamin B 12 deficiency and phenylketonuria

A fenilcetonúria, doença metabólica hereditária, autossômica recessiva, é a mais frequente das aminoacidopatias. Quando não diagnosticada e tratada precocemente, causa retardo mental grave. Os programas de triagem neonatal transformaram a histó- ria natural dessa doença, possibilitando o diagnóstico neonatal e a instituição imediata do tratamento dietético. Atualmente, os pacientes com controle adequado têm vida normal. Nas últimas décadas, alterações nutricionais têm sido relacionadas ao tratamento dietético e aos seus desvios, especialmente após a primeira década de vida. Neste artigo apresenta-se o caso de um adolescente que desenvolveu anemia megaloblástica por deficiente ingestão de vitamina B12 e uma revisão da literatura sobre o tema.(AU)

Phenylketonuria, inherited metabolic disease, autosomal recessive, is the most common of aminoacidopathies. If not diagnosed and treated early, causes severe mental retardation. The newborn screening programs have transformed the natural history of this disease, allowing the neonatal diagnosis and the immediate institution of dietary treatment. Currently, patients with adequate control have normal life. In recent decades, nutritional changes have been related to dietary treatment and its deviations, especially after the first decade of life. In this article we present the case of a teenager who developed megaloblastic anemia due to poor intake of vitamin B12 and a literature review on the topic(AU)

Anemia in severe acute malnutrition.

OBJECTIVES: India has the highest prevalence of severe acute malnutrition (SAM). Severe anemia is one of the comorbidities responsible for increased mortality in severely malnourished children, yet it has not received the attention it should. The aim of the present study was to determine the prevalence and type of anemia and to evaluate the possible etiologies for severe anemia, in these children. METHODS: A cross-sectional study of patients with SAM in a tertiary care hospital in northern India over a period of 12 mo from Sept. 1, 2010 to Aug. 31, 2011 was conducted. We observed the prevalence of severe anemia (hemoglobin < 7 g/dL), morphologic type of anemia, number of patients requiring blood transfusion, hematologic profile of mothers, nature of feeding, duration of exclusive breastfeeding, and the demographic profile of these patients. RESULTS: Included in the study were 131 cases of SAM. The age group varied between 6 and to 59 mo. Of patients with SAM, 67.3% had severe anemia; 13.8% had moderate anemia. Of these patients, 25% required packed red blood cell transfusion. The most common type of anemia was microcytic (38.6%) followed by megaloblastic (30.5%). CONCLUSIONS: A high incidence of severe anemia in SAM with a large proportion (25%) requiring blood transfusion is a pointer toward nutritional anemia being a very common comorbidity of SAM requiring hospital admission. Because megaloblastic anemia closely followed microcytic anemia, supplementation with vitamin B12 in addition to iron and folic acid would be recommended.

Does early treatment prevent deafness in thiamine-responsive megaloblastic anaemia syndrome?

Thiamine-responsive megaloblastic anaemia (TRMA; OMIM 249270) syndrome is an autosomal recessive disorder characterized by diabetes mellitus, megaloblastic anaemia, and sensorineural deafness. Progressive hearing loss is one of the cardinal findings of the syndrome and is known to be irreversible. Whether the deafness in TRMA syndrome can be prevented is not yet known. Here, we report a four-month-old female infant diagnosed with TRMA syndrome at an early age. There was no hearing loss at the time of diagnosis. The patient's initial auditory evoked brainstem response measurements were normal. Although she was given thiamine supplementation regularly following the diagnosis, the patient developed moderate sensorineural hearing loss at 20 months of age, indicating that early diagnosis and treatment with oral thiamine (100 mg/day) could not prevent deafness in TRMA syndrome. It would be premature to draw general conclusions from one case, but we believe that further patient-based observations can shed light on the pathophysiology of this rare syndrome as well as prediction of its prognosis.

Hemorrhagic manifestation of megaloblastic anemia: report of two cases and literature review.

Megaloblastic anemia is not uncommon in developing countries. Its presentation as thrombocytopenia and hemorrhagic manifestation are, however, rare. We describe the clinical scenario in two young patients who presented to the emergency room of Sir Ganga Ram Hospital, a tertiary care center in New Delhi, India, with pancytopenia and bleeding diathesis. Both patients improved after B12 supplementation. Reports of two cases and a brief review is presented.

[Galactosemia associated with Rogers syndrome in a 10-month-old infant]. / Galactosémie congénitale associée à un syndrome de Rogers chez une petite fille de 10 mois.

Galactosemia and congenital Rogers syndrome or thiamine-responsive megaloblastic anemia are 2 rare inherited metabolic diseases. The combination of the 2 diseases has never been reported in the literature. We describe the case of an infant followed for congenital galactosemia since the age of 8 days, with thiamine-responsive megaloblastic anemia diagnosed at the age of 10 months. Galactosemia's symptoms occur in the first 2 weeks of life with severe liver disease. Total eviction of the galactose allows complete regression and prevention of early symptoms but does not prevent late complications. Rogers syndrome associates megaloblastic anemia, deafness, and diabetes mellitus that begin in childhood. Supplementation with thiamine allows regression of anemia and prevents the onset of diabetes at least until adolescence.

Thiamine withdrawal can lead to diabetic ketoacidosis in thiamine responsive megaloblastic anemia: report of two siblings.

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.

Generalized hyperpigmentation of the skin due to vitamin B12 deficiency.

A 49-year-old man presented with neurosis, hyperpigmentation of the skin, and depigmentation of the hair. On examination, hyperpigmentation was observed on the oral mucosa and the skin of the forearms, elbows, palmar creases and periunguinal area, knees, and feet. He had megaloblastic anemia with a low serum level of vitamin B12 due to malabsorption resulting from a gastrectomy 10 years previously. His hyperpigmentation was resolved with vitamin B12 supplementation. Histology showed an increase of melanin in the basal layer. In electron microscopic study, many melanosomes were observed in melanocytes and surrounding keratinocytes. We consider that the dominant mechanism of hyperpigmentation due to vitamin B12 deficiency is not a defect in melanin transport but is rather an increase in melanin synthesis.

Mutations in a new gene encoding a thiamine transporter cause thiamine-responsive megaloblastic anaemia syndrome.

Thiamine-responsive megaloblastic anaemia syndrome (TRMA; MIM 249270) is an autosomal recessive disorder with features that include megaloblastic anaemia, mild thrombocytopenia and leucopenia, sensorineural deafness and diabetes mellitus. Treatment with pharmacologic doses of thiamine ameliorates the megaloblastic anaemia and diabetes mellitus. A defect in the plasma membrane transport of thiamine has been demonstrated in erythrocytes and cultured skin fibroblasts from TRMA patients. The gene causing TRMA was assigned to 1q23.2-q23.3 by linkage analysis. Here we report the cloning of a new gene, SLC19A2, identified from high-through-put genomic sequences due to homology with SLC19A1, encoding reduced folate carrier 1 (refs 8-10). We cloned the entire coding region by screening a human fetal brain cDNA library. SLC19A2 encodes a protein (of 497 aa) predicted to have 12 transmembrane domains. We identified 2 frameshift mutations in exon 2. a 1-bp insertion and a 2-bp deletion, among four Iranian families with TRMA. The sequence homology and predicted structure of SLC19A2, as well as its role in TRMA, suggest that its gene product is a thiamine carrier, the first to be identified in complex eukaryotes.

The gene mutated in thiamine-responsive anaemia with diabetes and deafness (TRMA) encodes a functional thiamine transporter.

Thiamine-responsive megaloblastic anaemia with diabetes and deafness (TRMA; MIM 249270) is an autosomal recessive disease thought to be due to a defect in thiamine (vitamin B1) transport. Pharmacological doses of thiamine correct the anaemia, and in some cases improve the diabetes, although progressive sensorineural deafness is irreversible. Previous studies localized the TRMA gene to a 4-cM region on chromosome 1q23.3 (ref. 5), and fine-mapping has recently narrowed that region further. We have previously demonstrated that fibroblasts from people with TRMA lack high-affinity thiamine transport. Expression of a gene encoding a known yeast thiamine transporter, THI10 (refs 8-10), in TRMA mutant cells prevents apoptotic cell death in thiamine-depleted medium. On the basis of these studies, we hypothesized that a defective thiamine transporter causes TRMA. We undertook a candidate gene approach to identify putative thiamine transporters in the 1q23.3 critical region. Here we present evidence that the gene SLC19A2 (for solute carrier family 19 (thiamine transporter), member 2) encodes the first known mammalian thiamine transporter, which we designate thiamine transporter-1 (THTR-1).

Bilateral retinal hemorrhages from megaloblastic anemia: case report and review of literature.

A 33-year-old woman who was a chronic alcohol abuser and had bilateral visual loss was found to have megaloblastic anemia with thrombocytopenia. Both fundi showed retinal venular dilatation and tortuosity, superficial and deep intraretinal hemorrhages, white-centered retinal hemorrhages, and optic disc edema. Her megaloblastic anemia was caused by vitamin B12 and folate deficiencies, resulting from an inadequate diet and alcohol abuse. The retinal changes were believed to be the result of the severe anemia and thrombocytopenia. Both the megaloblastic anemia and retinal changes resolved promptly after she received vitamin B12 and folate supplements. This case shows that megaloblastic anemia should be suspected as a cause of bilateral retinal hemorrhages.

Successful reversal by chelation therapy of congestive cardiomyopathy due to iron overload.

A patient who developed severe iron overload cardiomyopathy is described. Venesection could not be performed because the patient had chronic anemia. Deferoxamine mesylate, a chelating agent, was administered daily for more than 2 years and produced significant improvement in ventricular function which was associated with a biopsy-proven decrease in myocardial iron stores. This is the first reported case in which a severe cardiomyopathy due to iron overload was reversed by chelation therapy alone.

Brain damage in infancy and dietary vitamin B12 deficiency.

A case of the exclusively breast-fed infant of a vegetarian mother is reported. Neurological deterioration commenced between three and six months of age, and progressed to a comatose premoribund state by the age of nine months. Investigations revealed a mild nutritional vitamin B12 deficiency in the mother, and a very severe nutritional B12 deficiency in the infant, with severe megaloblastic anaemia. Treatment of the infant with vitamin B12 resulted in a rapid clinical and haematological improvement, but neurological recovery was incomplete. Evidence is presented that dietary B12 deficiency was the sole cause of the infant's deterioration, and the literature relating to the condition is reviewed. It is recommended that all strict vegetarians (vegans), especially women in the child-bearing age group, take vitamin B12 supplements.