Intelligence in adolescents with homozygous sickle cell (SS) disease

ABSTRACT

Strokes occur in approximately 8 percent of children with SS disease most commonly below age 15 years. The cause is generally cerebral infraction secondary to occlusion of major cerebral vessels. Less extensive cerebral lesions might also occur producing subtle defects of cerebral function. This hypothesis has been tested using the Wechsler Intelligence Scales-Revised (WISC-R) adjusted to Jamaican conditions in SS children and controls followed from birth in the Jamaican cohort study. The first 125 children with SS disease were each matched with 2 children of the same sex and age but with a normal haemoglobin (AA) genotype. IQ scores in 60 age/sex matched pairs (1SS; 1AA) of cohort children aged 15-18 years were normally distributed in both genotypes but average IQ was significantly lower in SS disease (p<0.01). The possible mechanism of this defect are being explored. (AU)