Hemoglobinopathy
Hemoglobinopathy is a kind of genetic defect that results in abnormal structure of one of the globin chains of the hemoglobin molecule. Common hemoglobinopathies include sickle-cell disease and thalassemia.
Symptoms
Most clinically significant hemoglobinopathies cause mild to acute anemia, in rare cases hemolytic anemia. Symptoms vary for the different diseases: in sickle cell disease the red blood cells tend to assume a different shape under anaerobic conditions, leading to organ damage and circulatory problems, while in thalassemia there is ineffective production of red blood cells (erythropoiesis).
Migration patterns
Migration patterns (Alkaline Electrophoresis)
In general on alkaline electrophoresis in order of increasing mobility are hemoglobins A2, E=O=C, G=D=S=Lepore, F, A, K, J, Bart's, N, I, and H.
In general a sickling test (sodium bisulfite) is performed on abnormal hemoglobins migrating in the S location to see if the red cells precipitate in solution.
Migration patterns (Acid Electrophoresis)
In general on acid electrophoresis in order of increasing mobility are hemoglobins F, A=D=G=E=O=Lepore, S, and C.
This is how abnormal Hgb variants are isolated and identified using these two methods. For example a Hgb G-Philadelphia would migrate with S on alkaline electrophoresis and would migrate with A on acid electrophoresis, respectively.
Common variants
- Hb S
- Hb C
- Hb E
- Hb D-Punjab
- Hb O-Arab
- Hb G-Philadelphia
- Hb Hasharon
- Hb Korle-Bu
- Hb Lepore
- Hb M
Hemoglobinopathy and evolution
Some hemoglobinopathies (and also related diseases like glucose-6-phosphate dehydrogenase deficiency) seem to have given an evolutionary benefit, especially to heterozygotes, in areas where malaria is endemic. Malaria parasites live inside red blood cells, but subtly disturb normal cellular function. In patients predisposed for rapid clearance of red blood cells, this may lead to early destruction of cells infected with the parasite and increased chance of survival for the carrier of the trait.
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Pathology: hematology (primarily C81-C96/200-208, D45-D47, D50-D77/280-289) |
| WBCs |
hematological malignancy (lymphoma, leukemia, multiple myeloma), myeloproliferative disease, myelodysplastic syndrome
-cytosis (Agranulocytosis, Leukocytosis, Lymphocytosis, Monocytosis) • -penia (Lymphopenia, Neutropenia) |
RBCs/anemia/
hemoglobinopathy |
nutritional anemia: Iron deficiency anemia, Plummer-Vinson syndrome, Megaloblastic anemia (Pernicious anemia)
hereditary hemolytic anemia: G6PD Deficiency, Thalassemia, Sickle-cell disease/trait, Hereditary spherocytosis, Hereditary elliptocytosis, Hereditary stomatocytosis
acquired hemolytic anemia: Autoimmune (Warm), HUS, MAHA, PNH, PCH
aplastic anemia: Acquired PRCA, Diamond-Blackfan anemia, Fanconi anemia • Sideroblastic anemia • Hemochromatosis |
| Coagulation/platelets |
coagulopathy: DIC • Hemophilia (A/VII, B/IX, C/XI, XIII) • Von Willebrand disease
Purpura: Henoch-Schönlein, ITP (Evans syndrome), TTP
primary hypercoagulable state: Protein C deficiency - Protein S deficiency - Antithrombin III deficiency - Antiphospholipid syndrome - Factor V Leiden
other hemorrhagic conditions: Bernard-Soulier syndrome - Glanzmann's thrombasthenia - Grey platelet syndrome |
| Histiocytosis |
WHO-I Langerhans cell histiocytosis - non-Langerhans-cell histiocytosis/WHO-II (Juvenile xanthogranuloma, Hemophagocytic lymphohistiocytosis) - malignant histiocytic disorders/WHO-III (Acute monocytic leukemia, Malignant histiocytosis, Erdheim-Chester disease) |
| Other |
Asplenia/hyposplenism - Methemoglobinemia |
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