Cognitive and Academic Functioning in Children With Sickle-Cell Disease

Comparing cognitive processing and academic functioning among children with sickle-cell syndrome and nondiseased siblings who were comparable in age, socioeconomic status, and sex, this study found that children with sickle-cell syndrome scored significantly lower than nondiseased siblings on a reading decoding achievement test and a sustained attention task associated with frontal-lobe functioning. No support was found for either the hypothesis of an age-related decrement of cognitive functioning or the hypothesis that youth with the homozygous condition (HbSS) would perform more poorly on cognitive and academic tasks than would children with heterozygous forms of sickle-cell syndrome (HbSC and HbS-beta thalassemia). The majority of measures were, however, related to social class, suggesting that there is variability in the cognitive functioning of youth in whom sickle-cell disease had been diagnosed which may, in part, be attributed to social class. The finding that hemoglobin is a predictor of intellectual functioning, fine-motor skills, and overall academic achievement was interpreted as suggesting that chronic reduced oxygen delivery may be etiologic and that therapeutic trials aimed at increasing hemoglobin levels should be undertaken.