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- What is septo-optic dysplasia?
Septo-optic dysplasia (SOD) includes midline defects of brain (absence of sep-
tum pellucidum, corpus callosum agenesis), optic nerve dysplasia, and pituitary
hypoplasia. Two out of these three abnormalities are required for the diagnosis
of SOD. Familial forms of SOD are caused by HESX1 transcription factor
defect and are associated with multiple pituitary hormone defi ciency including
vasopressin (Fig. 2.5 ).a bbFig. 2.4 ( a ) A 20-year-old male with short stature and delayed puberty due to multiple pituitary
hormone defi ciency. ( b ) Sagittal CEMRI showing small pituitary ( red arrow ), redundant stalk, and
ectopic posterior pituitary bright spot ( arrow head ) suggestive of pituitary transcription factor defect
2 Disorders of Growth and Development: Diagnosis and Treatment