“…1 However, an increasing number of early developmental transcription factors and associated pathway genes have been implicated in the etiology of SOD, ie, HESX1, SOX2, SOX3, OTX2, PROKR2, FGF1, and FGF8. [2][3][4] These genes are expressed in regions that determine the formation of forebrain and related midline structures, such as the hypothalamus and pituitary gland, and mutations in these genes are therefore associated with marked phenotypic heterogeneity. Classically, the diagnosis of SOD is made when 2 or more features of the classic triad of optic nerve hypoplasia, pituitary hormone abnormalities, and midline brain defects are present.…”