Spontaneous, simultaneous bilateral osteonecrosis of the femoral heads in a patient with sideroblastic anaemia with B-cell immunodeficiency, periodic fever and developmental delay syndrome.

Sideroblastic anaemia with B-cell immunodeficiency, periodic fever and developmental delay is a recently described, rare syndrome characterised by numerous manifestations underpinned by mutations in transfer RNA nucleotidyltransferase. The pathogenesis arises from mitochondrial dysfunction, with impaired intracellular stress response, deficient metabolism and cellular and systemic inflammation. This yields multiorgan dysfunction and early death in many patients with survivors suffering significant disability and morbidity. New cases, often youths, are still being described, expanding the horizon of recognisable phenotypes. We present a mature patient with spontaneous bilateral hip osteonecrosis that likely arises from the impaired RNA quality control and inflammation caused by this syndrome.

Clinical and Therapeutic Aspects of Sideroblastic Anaemia with B-Cell Immunodeficiency, Periodic Fever and Developmental Delay (SIFD) Syndrome: a Systematic Review.

BACKGROUND AND PURPOSE: Sideroblastic anaemia with B-cell immunodeficiency, periodic fever and developmental delay (SIFD) syndrome is a novel rare autoinflammatory multisystem disorder. We performed a systematic review of the available clinical and therapeutics aspects of the SIFD syndrome. METHODS: A systematic review according to PRISMA approach, including all articles published before the 30th of July 2021 in Pubmed and EMBASE database, was performed. RESULTS: The search identified 29 publications describing 58 unique patients. To date, 41 unique mutations have been reported. Onset of disease is very early with a median age of 4 months (range 0-252 months). The most frequent manifestations are haematologic such as microcytic anaemia or sideroblastic anaemia (55/58), recurrent fever (52/58), neurologic abnormalities (48/58), immunologic abnormalities in particular a humoral immunodeficiency (48/58), gastrointestinal signs and symptoms (38/58), eye diseases as cataract and retinitis pigmentosa (27/58), failure to thrive (26/58), mucocutaneous involvement (29/58), sensorineural deafness (19/58) and others. To date, 19 patients (35.85%) died because of disease course (16) and complications of hematopoietic cell stems transplantation (3). The use of anti-TNFα and hematopoietic cell stems transplantation (HCST) is dramatically changing the natural history of this disease. CONCLUSIONS: SIFD syndrome is a novel entity to consider in a child presenting with recurrent fever, anaemia, B-cell immunodeficiency and neurodevelopmental delay. To date, therapeutic guidelines are lacking but anti-TNFα treatment and/or HCST are attractive and might modify the clinical course of this syndrome.

A Rare Autoinflammatory Disorder in a Pediatric Patient with Favorable Response to Etanercept: Sideroblastic Anemia with B Cell Immunodeficiency, Periodic Fevers, and Developmental Delay Syndrome.

Introduction: Sideroblastic anemia with B cell immunodeficiency, periodic fevers, and developmental delay (SIFD) syndrome is caused by biallelic TRNT1 mutations. TRNT1 gene encodes a CCA-adding tRNA nucleotidyl transferase enzyme. Mutant TRNT1 results in immunodeficiency and anemia in various degrees, accompanied by several organ involvement. Case Presentation: We present here a 15-month old male, demonstrated brittle hair, growth hormone deficiency, recurrent fever, arthritis, recurrent infections, mild anemia, and hypogammaglobulinemia. The patient did not respond to colchicine treatment, and after establishing SIFD diagnosis with the presence of homozygote c.948-949delAAinsGG (p.Lys317Glu) mutation in TRNT1 gene, we commenced monthly intravenous immunoglobulin replacement and weekly subcutaneous etanercept. A rapid resolution of fever episodes and infections occurred after initiation of this treatment regimen. Afterward, both anemia and growth parameters have improved during follow-up. Conclusion: SIFD syndrome should be considered in patients with recurrent fever, arthritis, and growth retardation even in the absence of severe anemia and prominent hypogammaglobulinemia.

Decompensation of cardiorespiratory function and emergence of anemia during pregnancy in a case of mitochondrial myopathy, lactic acidosis, and sideroblastic anemia 2 with compound heterozygous YARS2 pathogenic variants.

Myopathy, lactic acidosis, and sideroblastic anemia 2 (MLASA2) is an autosomal recessive mitochondrial disorder caused by pathogenic variants in YARS2. YARS2 variants confer heterogeneous phenotypes ranging from the full MLASA syndrome to a clinically unaffected state. Symptom onset is most common in the first decade of life but can occur in adulthood and has been reported following intercurrent illness. Early death can result from respiratory muscle weakness and cardiomyopathy. We report a case of MLASA2 with compound heterozygous YARS2 pathogenic variants; a known pathogenic nonsense variant [NM_001040436.3:c.98C>A (p.Ser33Ter)] and a likely pathogenic missense variant not previously associated with disease [NM_001040436.3:c.948G>T (p.Arg316Ser)]. The proband initially presented with a relatively mild phenotype of myopathy and lactic acidosis. During pregnancy, anemia emerged as an additional feature and in the postpartum period she experienced severe decompensation of cardiorespiratory function. This is the first reported case of pregnancy-related complications in a patient with YARS2-related mitochondrial disease. This case highlights the need for caution and careful counseling when considering pregnancy in mitochondrial disease, due to the risk of disease exacerbation and pregnancy complications.

Sideroblastic anaemia in a patient with sickle cell disease.

Sideroblastic anaemia is a rare condition. We report a unique case of concomitant sideroblastic anaemia in a patient with sickle cell disease with long-standing blood transfusion history. Due to a low prevalence of sideroblastic anaemia, the diagnosis of sideroblastic anaemia is often difficult, especially when coexisting with common types of anaemia, including sickle cell disease. This case highlights the detrimental effects of anchoring bias. Rare causes of refractory anaemia should be considered in patients with haemoglobin disorders as the therapeutic approaches for these conditions are different. High suspicion on the part of the clinician and low threshold for workup of anaemia often aids in the diagnosis of coexisting conditions such as sideroblastic anaemia. Early diagnosis and treatment of sideroblastic anaemia improves patient outcomes and prevents long-term complications.

[A microcytic sideroblastic anemia successfully treated with B6 vitamin]. / Une anémie microcytaire sidéroblastique carentielle traitée efficacement par de la vitamine B6.

INTRODUCTION: Sideroblastic anemia is a rare cause of microcytic anemia, which is characterized by ring sideroblasts on bone marrow aspirate. This anemia can be congenital or acquired. CASE REPORT: We report the case of an alcoholic 49-year-old man who presented with a severe microcytic sideroblastic anemia related to pyridoxine (B6 vitamin) deficiency. Acid folic deficiency was associated. The blood count normalized within one month after vitamin supplementation. CONCLUSION: Pyridoxine deficiency must be sought in sideroblastic anemia in patients at risk.

SIFD as a novel cause of severe fetal hydrops and neonatal anaemia with iron loading and marked extramedullary haemopoiesis.

SIFD describes a heritable, syndromic condition characterised principally by sideroblastic anaemia (SA) with immunodeficiency, fevers and developmental delay, arising in mutations within the TRNT1 gene. Other clinical manifestations of SIFD include cardiomyopathy, seizures, sensorineural hearing loss, renal dysfunction, metabolic abnormalities, hepatosplenomegaly and retinitis pigmentosa.Presentation of SIFD is variable but typically in early childhood with SA or with fever. In this report, we extend the described SIFD phenotype. We describe a kindred in which the index case presented with fetal hydrops, and early neonatal death, and the second child had severe anaemia at delivery. Both cases had prominent extramedullary erythropoiesis and numerous circulating nucleated red blood cells.

A novel mutation in NDUFB11 unveils a new clinical phenotype associated with lactic acidosis and sideroblastic anemia.

NDUFB11, a component of mitochondrial complex I, is a relatively small integral membrane protein, belonging to the "supernumerary" group of subunits, but proved to be absolutely essential for the assembly of an active complex I. Mutations in the X-linked nuclear-encoded NDUFB11 gene have recently been discovered in association with two distinct phenotypes, i.e. microphthalmia with linear skin defects and histiocytoid cardiomyopathy. We report on a male with complex I deficiency, caused by a de novo mutation in NDUFB11 and displaying early-onset sideroblastic anemia as the unique feature. This is the third report that describes a mutation in NDUFB11, but all are associated with a different phenotype. Our results further expand the molecular spectrum and associated clinical phenotype of NDUFB11 defects.