Angiotensinogen M235T Gene Polymorphism is a Genetic Determinant of Cerebrovascular and Cardiopulmonary Morbidity in Adolescents with Sickle Cell Disease.

BACKGROUND

Cerebrovascular stroke is a common critical complication of sickle cell disease (SCD). Angiotensinogen (AGT) M235T gene polymorphism is associated with risk of ischemic stroke and cardiovascular disease.

AIM

We investigated the potential association between angiotensinogen M235T gene polymorphism and susceptibility to cerebrovascular and cardiopulmonary complications in adolescents with SCD.

METHODS

Forty-six patients with SCD in steady state were studied stressing on history of stroke, hydroxyurea/chelation therapy, hematological profile, and echocardiographic findings. Polymerase chain reaction-based restriction fragment length polymorphism analysis was used to detect AGT M235T gene polymorphism. Fifty sex- and age-matched healthy controls were enrolled for assessment of M235T gene polymorphism pattern.

RESULTS

The distribution of AGT M235T gene polymorphism was similar between SCD patients and healthy controls. The frequency of T allele of AGT M235T gene polymorphism (TT and MT genotypes) was significantly higher among patients with history of manifest stroke (P < .001). Patients with TT and MT genotypes had higher incidence of cardiopulmonary complications (P = .041) as well as higher percentage of HbS (P < .001) and lower hemoglobin level (P = .008) compared with those with MM genotype. Serum ferritin, liver iron concentration, and cardiac T2* were not related to T alleles or genotypes. Logistic regression analysis revealed that M235T genotype was a significant independent factor related to the occurrence of stroke among patients with SCD (Odds Ratio 14.05, 95% confidence interval 3.82-28.91; P = .001).

CONCLUSION

AGT M235T gene polymorphism may represent a genetic modifier to vascular morbidities in Egyptian patients with SCD.