Endothelial nitric oxide synthase gene intron 4 variable number tandem repeat polymorphism in β-thalassemia major: relation to cardiovascular complications

Pathogenic Mechanisms in Thalassemia I: Ineffective Erythropoiesis and Hypercoagulability

Erythropoiesis is the physiological process that results in the production of red blood cells (RBCs). In conditions of pathologically altered erythropoiesis or ineffective erythropoiesis, as in the case of β-thalassemia, the reduced ability of erythrocytes to differentiate, survive and deliver oxygen stimulates a state of stress that leads to the ineffective production of RBCs. We herein describe the main features of erythropoiesis and its regulation in addition to the mechanisms behind ineffective erythropoiesis development in β-thalassemia. Finally, we review the pathophysiology of hypercoagulability and vascular disease development in β-thalassemia and the currently available prevention and treatment modalities.

Endothelial nitric oxide synthase gene polymorphism (786T/C) in childhood acute lymphoblastic leukemia survivors

OBJECTIVES

To detect eNOS gene polymorphism and its relation to cardiovascular complications in pediatric acute lymphoblastic leukemia (ALL) survivors.

METHODS

CBC, renal and liver function tests, lipid profile, Carotid artery Intima Media Thickness (CIMT), and Brachial artery Intima Media Thickness (BIMT). eNOS gene polymorphism was done in 40 childhood ALL survivors and 40 controls.

RESULTS

There was no significant difference between survivors and control groups regarding 786 T/C polymorphism. There was a significant increase in serum cholesterol, TGs, LDL, VLDL, and HbA1c in the TC and CC group more than in the TT group, while there was a significant decrease in serum HDL in the TC and CC group more than in the TT group. There was no significant difference as regards echocardiography findings between different polymorphisms of 786 T/C, but there was a significant difference between 786 T/C groups with regard to the carotid and brachial arteries intima media thickness (IMT) measurements being significantly higher in the TC and CC group more than in the TT group.

CONCLUSION

Carotid and brachial arteries intima media thickness measurements were higher in the survivors when compared to healthy controls. eNOS gene polymorphism may play a role in modifying or developing CVD in pediatric ALL survivors.