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Carrier Screening For Inherited Genetic Conditions
Published in Vincenzo Berghella, Obstetric Evidence Based Guidelines, 2022
Whitney Bender, Lorraine Dugoff
Beta-thalassemia is also caused by a mutation in the beta-globin gene on chromosome 11. This results in the inability to produce hemoglobin A. Individuals who are heterozygous for this mutation have beta-thalassemia minor. Depending upon the amount of normal beta-globin chain production, disease severity varies. Typically, asymptomatic mild anemia is present. Individuals who are homozygous for this mutation have beta-thalassemia major, or Cooley anemia. This disease is characterized by severe anemia with extramedullary hematopoiesis, delayed sexual development, and poor growth. Although elevated levels of Hb F are produced in an attempt to compensate for the absence of Hb A, this condition is universally fatal in late childhood unless treatment with periodic blood transfusions is initiated early. See Chap. 14 in Maternal-Fetal Medicine Evidence Based Guidelines.
Endocrine Glands
Published in Pritam S. Sahota, James A. Popp, Jerry F. Hardisty, Chirukandath Gopinath, Page R. Bouchard, Toxicologic Pathology, 2018
Richard A. Peterson, Sundeep Chandra, Mark J. Hoenerhoff
Extramedullary hematopoiesis: Extramedullary hematopoiesis is occasionally observed in the adrenal cortex in rodents and may contain erythrocytic and/or granulocytic cells. This change must be differentiated from inflammation. When it is found in the adrenal gland, usually, prominent extramedullary hematopoiesis is also present in the spleen (Frith et al. 2000).
Clinical Considerations
Published in Stephen W. Carmichael, Susan L. Stoddard, The Adrenal Medulla 1986 - 1988, 2017
Stephen W. Carmichael, Susan L. Stoddard
King, Kopecky, Baker et al. (1987) described a patient with agnogenic myeloid metaplasia who was discovered by CT to have bilateral asymmetric adrenal enlargement. CT-guided needle biopsy demonstrated hematopoietic cells in the adrenal gland. By using CT and cytologic findings, they diagnosed extramedullary hematopoiesis.
Thrombocytosis in an infant with a TRPV4 mutation: a case report
Published in Platelets, 2021
Christopher S. Thom, Erik Brandsma, Michele P. Lambert
Benign thrombocytosis may be a clinical component of TRPV4-associated metatropic dysplasia. Thrombocytosis observed in this case may have resulted from altered extracellular matrix stiffness and megakaryocyte reactivity, in agreement with cellular and murine phenotypes[3]. However, we cannot exclude chronic inflammation or respiratory support as potential confounders. Reactive thrombocytosis can occur in the setting of inflammation [14] or lung injury[15]. However, the magnitude and duration of this patient’s thrombocytosis is outside the range of what we typically encounter in infants with lung disease. Notably, the platelet count was within the normal range for the first few days of this patient’s life (Figure 1). This may represent relatively depressed platelet count values shortly after birth in this preterm infant, or alternatively reflect a postnatal reactive thrombocytosis. Indeed, one might expect a TRPV4 gain-of-function mutation to have made our patient more susceptible to reactive thrombocytosis. A small focus of extramedullary hematopoiesis was identified on autopsy of the lung in this patient, but we suspect that this was most likely an incidental finding of limited clinical consequence.
Relation of Serum Ferritin Level with Serum Hepcidin and Fucose Levels in Children with β-Thalassemia Major
Published in Hemoglobin, 2021
Salah H. AL-Zuhairy, Mohammed A. Darweesh, Mohammed A-M. Othman
The main pathophysiology of homozygous β-thal is reduced amount (β+) or absent (β0) of β-globin chains result in unbalanced α- and β-globin chains where unbound α-globin chains appear to be in relative excess [2,4]. The α/β chain imbalance is responsible for the hemolysis of red blood cells (RBCs) and for apoptosis of erythroid precursors in the bone marrow and at extramedullary sites [2]. The α-globin chain aggregates form inclusion bodies within RBCs and immature developing erythroblasts responsible for oxidative stress and membrane damage. These events are followed by the premature death of many late erythroid precursors in the bone marrow and spleen resulting in ineffective erythropoiesis. The anemia and resulting hypoxia lead to a dramatic increase in serum erythropoietin levels in an attempt to compensate for the reduced oxygen-carrying capacity. The marked increase in erythropoietin stimulation, if it is not inhibited by proper transfusion therapy, can lead to uncontrolled expansion of erythroid precursors in the marrow as well as in other sites, such as the spleen and liver, leading to extramedullary hematopoiesis (EMH) [1,5]. Extramedullary hematopoiesis is particularly common in nontransfusion-dependent thalassemia (NTDT) patients (20.0%) but rarely occurs (<1.0%) in patients with transfusion-dependent thalassemia (TDT), who also exhibit underlying bone marrow suppression due to transfusion therapy [6]. Unfortunately, in Iraq, no detailed demographic data on β-thal major (β-TM) or β-thal intermedia (β-TI) patients with EMH are currently available.
Cellular kinetics of hematopoietic cells with Sfpi1 deletion are present at different frequencies in bone-marrow and spleen in X-irradiated mice
Published in International Journal of Radiation Biology, 2020
Reo Etani, Mitsuaki Ojima, Kentaro Ariyoshi, Yohei Fujishima, Michiaki Kai
Bone marrow is the major site of hematopoiesis during adulthood. HSCs remain in the bone marrow because of the supportive microenvironment called the niche, and their proliferation and differentiation are controlled to maintain hematopoietic function (Bowman and Zon 2009). Hematopoietic homeostasis is thought to be altered if the function of the niche is impaired. HSCs can migrate from the bone marrow through the bloodstream to repopulate populations outside the bone marrow (Hanks 1964; Croizat et al. 1980; Fliedner 1998; Fliedner et al. 2002). Extramedullary hematopoiesis may occur in organs such as the spleen, reflecting a pathological condition and poor hematopoietic function (Lewis et al. 1994; Schnuelle et al. 1999). Moreover, excessive hematopoietic stress mobilizes HSCs from bone marrow to the spleen and induces extramedullary hematopoiesis (Inra et al. 2015). In this study, the bone marrow niche may have been damaged by high-dose X-irradiation, resulting in a shift in the site of hematopoiesis from bone marrow to the spleen. If the major site of hematopoiesis shifts from bone marrow to the spleen, HRCs with HDSG may also migrate from bone marrow to the spleen. HRCs that have migrated to the spleen may continue nonselective proliferation and differentiation to maintain hematopoietic function regardless of the presence or absence of HDSG. Thus, HRCs with HDSG may remain in the spleen if cell competition does not occur, and new HDSG may be caused by excessive hematopoietic stress after X-irradiation.