Given the difference in tNAA, tCr and GSH between FHD groups, the lack of group difference in metabolite concentrations based on APOE4 status may be considered surprising; it is not however incongruent with the current literature, in which the relationship between APOE4 and metabolite concentrations is not straightforward. This evidence concerns the gene APOE and hypoalphalipoproteinemia, primary, 1.