Terms : Hide Images
| 4141280917 | Hemoglobinopathies | Inherited mutations in the coding sequences of globin genes that may alter the protein structure and result in disease. Clinically significant hemoglobin variants result in distinct syndromes including variable hemolysis, erythrocytosis, or cyanosis | 0 | |
| 4141288364 | Thalassemia | Most common single gene disorders in the world. Genetic defect in hemoglobin synthesis. Characterized by absent or diminished production of one of the hemoglobin chains, resulting in an imbalance in globin chains leading to globin precipitation in erythrocytes and accelerated destruction of the microcytic, hypochromic red cells. | 1 | |
| 4141294390 | Microcytic | Small RBCs | 2 | |
| 4141294391 | Hypochromic | Pale RBCs | 3 | |
| 4141301064 | Alpha thalassemia | Predominately due to deletions of one or more of the four gene coding for the a chain. Deletions of one or two a globin chains are virtually asymptomatic. Deletion of more than that are symptomatic. | 4 | |
| 4141305782 | Hemoglobin H disease | Due to deletion of three a globin genes. Presents as moderately severe anemia with splenomegaly and hypochromic microcytic red cells. | 5 | |
| 4141311238 | When is a thalassemia incompatible with life? | when all four of the a globin genes are deleted. Fetus is a still born. This is called hemoglobin Barts, and causes hydrops fetalis. | 6 | |
| 4141315051 | Beta thalassemia | Present disparate molecular defects in B globin gene that culminates in a decrease or absence of B chain production. mostly due to point mutations. Reduced/absent B chains leads to a chain inclusions, which cause apoptosis in the bone marrow and enhanced intramedullary destruction of developing erythroid cells. | 7 | |
| 4141332616 | Diagnosis of B thalassemia | Relies on clinical features: Low MCV, poikilocytosis (variation in red cell shape) and increased percentages of hemoglobin A2 or hemoglobin F. Also with restriction length polymorphisms. | 8 | |
| 4141337611 | Thalassemia Major | Most severe form of B thalassemia-homozygous B0 thalassemia. Patients are completely dependent on transfusions. Have skeletal abnormalities due to overproduction of RBCs in the marrow space (chipmunk facies). | 9 | |
| 4141421917 | Thalassemia minor | Mild, eg a-Thalassemia trait, B Thalassemia trait | 10 | |
| 4141423868 | Thalassemia intermedia | Intermediate severity, eg homozygous B+ thalassemia | 11 | |
| 4141424992 | Treatment of thalassemias | Intensive transfusion programs. Eventually patients will die of complications of iron overload unless chelation therapy with oral deferasirox is started. | 12 | |
| 4141434054 | Iron overload can be associated with | heart failure, cirrhosis of the liver, diabetes mellitus, failure of sexual maturation, and hypoparathyroidism | 13 | |
| 4141439072 | Treatment of severe B thalassemia | Any treatment that increases Y chain synthesis or decreases a chain synthesis could be of marked benefit for these patients. | 14 | |
| 4141441571 | Sickle hemoglobin (Hb S) | Most common of the hemoglobinopathies worldwide. Results from substitution of hydrophobic valine for normal glutamic acid at position 6 of the B globin chain. Pathophys: Intracellular polymer formation changes properties of the red cells and results in abnormal shape and accelerated RBC destruction. Deformity makes it hard for RBCs to pass through micro-circulation--> increased blood viscosity. Activated adhesion molecules due to chronic inflammation and resulting high white blood cell count. Decreased NO level contributing to vasoconstriction. | 15 | |
| 4141445325 | Four genotypes of Hb S | 1) homozygous sickle cell disease (SS) 2) Sickle cell Hb C (SC) disease 3) Sickle cell B+ (S B+) thalassemia 4) Sickle cell B0 (S B0) thalassemia (One Bs chain, no normal B chain) Sickle cell trait: One Bs chain and one normal B chain-asymptomatic | 16 | |
| 4141458970 | Clinical features of sickle cell anemia | result from vasoocclusion in small vessels, resulting in infarcts, and hemolysis. PAIN. Kids can get hand foot syndrome. Also can get abrupt onset of massive splenomegaly. Adults can get acute chest syndrome. HEMOLYSIS | 17 | |
| 4143318154 | Hemolysis and sickle cell | Associated with the premature destruction of sickled red cells, which have an average survival of only 20 days compared to usual 120 days. Can be accelerated in illnesses such as infections. | 18 | |
| 4143333106 | Diagnosis of sickle hemoglobinopathies | Made by the identification of the presence of Hb S in a lysate prepared from red cells. | 19 | |
| 4143338554 | Treatment of sickle cell anemia | Pain relief generally through narcotics. Penicillin prophylaxis in kids. Red cell exchange transfusions, but these have no impact in the acute treatment of sickle cell pain crisis. Hydroxyurea, a ribonucleotide reductase inhibitor, reduces severity of pain. Hematopoietic stem cell transplantation can cure sickle cell anemia. But these are hard to come by and not always successful. | 20 | |
| 4143360865 | Complications of red cell transfusions | Development of alloimmunization (antibody formation directed against transfused red cells). Could lead to iron overload. | 21 | |
| 4143378375 | Hemoglobin C disease | Mutation in nucleotide triplet (GAG -> AAG) that messes up the B globin chain. Hb CC red cells are trapped in the spleen. Patients get partially compensated hemolytic anemia and mild to moderate splenomegaly. | 22 | |
| 4143399078 | Unstable hemoglobinopathies | Abnormal hemoglobins precipitate either spontaneously or under oxidative stress, forming hemoglobin inclusions (Heinz bodies) which impair red cell deformability and result in enhanced clearance. Treatment involved folate supplementation, transfusion support, and avoidance of oxidant agents. | 23 | |
| 4143434278 | M hemoglobin variants | Prosthetic heme moiety is stabilized the ferric state (methemoglobin). Results in hemoglobin species incapable of the reversible binding of oxygen. Results in asymptomatic cyanosis. Treatment not required. | 24 | |
| 4143451957 | Megaloblastic anemias | Large immature red blood cells (megaloblasts) because impaired DNA synthesis. Maturation of nucleus is delayed compared to the maturation of the cytoplasm. Pancytopenia will occur. Three causes: 1) Folate deficiency 2) Vit B12 deficiency 3) Orotic aciduria See macrocytic anemia with oval macrocytes in the peripheral blood. Can cause glossitis, a beefy red sore tongue. | 25 | |
| 4143479050 | Clinical features of vitamin B12 deficiency | Macrocytic anemia, paresthesia in extremities, decreased vibratory sense and proprioception, ataxia, and neuropyschiatric abnormalities. Develops gradually. | 26 | |
| 4143495961 | Causes of vitamin B 12 deficiency | 1) Dietary deficiency (very rare) 2) Deficiency of intrinsic factor pernicious anemia gastrectomy 3) Ileal malabsorption, ileal resection, Crohn's disease, fish tapeworm, bacterial overgrowth in bowel | 27 | |
| 4143504146 | Pernicious anemia | Decrease in number of red blood cells due to atrophy of gastric parietal cells and therefore they do not make intrinsic factor. Intrinsic factor is what absorbs vit B12. A type of megaloblastic anemia. Recessive inherited disorder, or due to an autoimmune disorder. Cause: Vit B12 deficiency Diagnose: 2/3 of patients have anti-intrinsic factors in serum or gastric juice. | 28 | |
| 4143521480 | Folate deficiency | Folate is necessary for DNA synthesis and is absorbed in the proximal jejunum. Clinical features: Megaloblastic anemia, elevated LDH,a dn low serum folate. | 29 |
