Studies in sickle-cell anemia. VIII. Further observations on the clinical manifestations of sickle-cell anemia in children.

Abstract

INTRODUCTION Genetically, sickle-cell anemia was probably first introduced into the United States in 1619, when the first African slaves were brought to the colonies. The initial clinical description was recorded by Herrick in 1910. 1 The asymptomatic trait has been found to occur in 7% to 10% of Negroes in this country. 2 Sickle-cell anemia fortunately is much less prevalent; it is estimated that between 30,000 and 100,000 individuals suffer from this disease in the United States. 3 It is now generally accepted that the gene responsible for sickling produces the asymptomatic trait when present in the heterozygous state 4 and active sickle-cell disease when it occurs in the homozygous state. The red blood cells in both sickle-cell anemia and the sickling trait contain an abnormal hemoglobin (S hemoglobin) and are capable of distorting their shape when exposed to reduced oxygen tension. The red blood cells in persons with the