A hemoglobinopathy is a genetic disorder which alters the structure of hemoglobin 1. The result is reduced oxygen-carrying capacity of the blood to the tissues, and other sequelae.
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Clinical presentation
Clinical presentation varies, is related to hypoxia, and characteristically includes the following:
claudication
tachycardia
dyspnea
vertigo
Pathology
vascular occlusion leading to infarcts
necrosis
osteomyelitis (100x more likely in sickle cell disease patients) 2
Types
Types of hemoglobinopathies include the following, with the predominant type of abnormal hemoglobin in parentheses following the disorder.
sickle cell trait (HbAS)
sickle cell-thalassemia (HbS and HbA)
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alpha thalassemia (deficient alpha-globin chain synthesis)
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beta thalassemia (deficient beta-globin chain synthesis)
thalassemia major (homozygous) - Cooley anemia
thalassemia minor (heterozygous)
hemoglobin C disease (HbCC)
hemoglobin C trait (HbAC)
Radiographic features
The radiographic features of hemoglobinopathies vary and some are more specific for specific hemoglobinopathies (e.g. splenic sequestration in sickle cell). Generally, many common radiographic features are related to extramedullary hematopoiesis and infarctions as follows:
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hair-on-end appearance (characteristic, not pathognomonic, of thalassemia)
rib expansion
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calvarial alterations
outer table thinning
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facial bone alterations
nasal and temporal bone expansion (obliteration of sinuses)
lateral displacement of orbits (hypertelorism)
dental displacement
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infarctions
epiphyseal ischemia (especially in the femoral head)
growth disturbances
osseous insufficiency
hand-foot syndrome (characteristic of sickle cell disease)