The mutant allele of the G894T polymorphism of NOS3, which results in a glutamate to aspartate conversion at codon 298 (Glu298Asp) [40], has a higher prevalence in several cardiovascular diseases [24,40-46] as well as other diseases with endothelial dysfunction such as diabetic nephropathy [47] and frontotemporal lobar degeneration [48]. This evidence concerns the gene NOS3 and endothelial dysfunction.