APOLIPOPROTEIN-E EPSILON-4 ALLELE AND HIPPOCAMPAL VOLUME IN TWINS WITH NORMAL COGNITION

We examined the relation of APOE-epsilon 4, hippocampal volume, and co gnitive performance in ten pairs of cognitively normal twins who had a mean age of 62.5 years (SD = 7.8). There were no significant differen ces in neuropsychological measures of the groups categorized by the pr esence of an epsilon 4 allele. However, the mean normalized right and left hippocampal volumes were smaller in the epsilon 4 group compared to the group without epsilon 4. Combined with prior reports, these fin dings suggest that epsilon 4 is associated with differences in brain m orphology that may be evident when no symptoms of dementia are present .