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.