M, male; F, female; FH, family history; H/O, history of; HU, hydroxyurea; BMI, body mass index; BP, blood pressure; HB, hemoglobin (steady state); Hct, hematocrit; WBCs, white blood cells; Retics, reticulocytes; PLT, platelets; HBF, hemoglobin F; LDH, lactate dehydrogenase; eGFR, estimated glomerular filtration rate; MA, microalbuminuria (ACR of 30-300 mg albumin/g creatinine); SCD: sickle cell disease, VOC: vaso-occlusive crisis, SSC: splenic sequestration crisis, ACS: acute chest syndrome, GS: gallstones, AVN: avascular necrosis. This evidence concerns the gene ALB and avascular necrosis.