A recent study of candidate genes associated with age onset of menarche assigned 42 SNPs of 9 genes (FSHB, LHCGR, POMC, UGT2B4, GHRH, CD40LG, FGFR1, KISS1, NKX2-1) among Caucasian normal females.29 Thus, the present finding of association between eNOS gene and menarche, assign eNOS gene to be an additional genetic modulator of menarche in SCD females. The gene discussed is NKX2-1; the disease is Schnyder corneal dystrophy.