Polymorphisms in the heme oxygenase-1 and bone morphogenetic protein receptor type 1b genes and estimated glomerular filtration rate in Brazilian sickle cell anemia patients Okeke Chinedu; Wouitchékpo Vincent Tonassé; Dulcinéia Martins Albuquerque; Igor de Farias Domingos; Aderson da Silva Araújo; Marcos André Cavalcanti Bezerra; Maria de Fátima Sonati; Magnun Nueldo Nunes dos Santos;