الفهرس 
IntroductionOnly 14 pages are availabe for public view
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Abstract
Hemoglobinopathies are diseases caused by genetic mutations that result in abnormal, dysfunctionl hemoglobin molecules or lower level of normal hemoglobin molecules, the most common hemoglobinopathies are sickle cell disease (SCD) and the thalassemias. In SCD, an abnormal hemoglobin alters the erythrocyte causing a chronic hemolytic anemia which can lead to pulmonary parenchymal damage and impaired vascular function. Pulmonary complications of SCD include acute chest syndrome, reactive airway disease, pulmonary hypertension, and pulmonary fibrosis. Both alpha and beta thalassemia are characterized by impaired production of hemoglobin subunits and severity of disease varies widely. Although screening studies suggest that pulmonary hypertension is a common complication for patients with thalassemia, its impact on survival is unkown. Pulmonary complications are responsible for significant morbidity and mortality accounting for 21-85% of deaths among chronic hemolytic anemia , chronic lung disease is thought to result from repeated lung damage caused by pulmonary vaso-occlusion and is characterized by abnormal lung function test values, chronic hypoxia, pulmonary hypertension, diffuse interstitial fibrosis and core pulmonale . The pattern of pulmonary dysfunction in βthalassemia is mostly restrictive, with some researchers reporting obstructive pattern. While Obstructive changes are typically seen in young children with SCD, whereas a restrictive pattern dominates in older children with SCD.