In adult populations, one of the most frequently studied genes has been apolipoprotein E (apoE), which modulates risk for Alzheimer’s disease. Carriers of the four allele of apoE have increased risk, whereas carriers of the two allele are possibly at decreased risk. To explore whether apoE alleles have distinct neuroanatomic signatures identifiable in childhood and adolescence, we examined 529 scans from 239 healthy subjects aged 4–20 years (Shaw et al. 2007). Although there were no significant IQ–genotype interactions, there was a step wise effect on cortical thickness in the entorhinal and right hippocamapal regions, with the four group exhibiting the thinnest, the three homozygotes in the middle range, and the two group the thickest. These data suggest that pediatric assessments might 1 day be informative for adult-onset disorders.
