A comparison of the physical and intellectual development of black children with and without sickle cell trait

Sickle cell trait, a condition present in 7% to 9% of the United States Black population, is usually considered to be a clinically benign condition. However, there is increasing evidence to indicate the contrary, that is, the clinical pathophysiology is variable, ranging from a benign condition in most cases to a relatively few cases of severe pathological involvement. Physical and intellectual growth measures were taken on 19 children with sickle cell trait (12 boys and 7 girls) from a large study of Black same sex twin pairs from Philadelphia, Pennsylvania, and compared to measures taken of a sample of normal Black children from 155 monozygotic and dizygotic same sex twin pairs. Sickle cell trait carriers were found to weigh less, have smaller upper arm circumference, lesser skinfold thickness, and showed less mature skeletal age, differing significantly from normal children. Sickle cell carriers tended to score lower on 4 of 5 intellectual measures, scoring one fifth to one third of a standard deviation lower than normal children.