NOS3 and cerebrovascular disorder: So far, several gene polymorphisms of NOS3 have been found to be associated with cerebrovascular disease: Glu298Asp, also known as E298D, or G894T (rs1799983) in exon 7; a variable number of 27 bp nucleotide tandem repeat sequences (VNTR, 27pb) in intron 4; and T786C polymorphism (rs2070744) in the 5′ region of NOS3 (10).