WFS1 and Leber hereditary optic neuropathy: Congenital CDI (10%) occurs due to mutations in the AVP-NPII gene1 [4], or wolframin (WFS1) gene (Wolfram syndrome) [3]. Wolfram or DIDMOAD syndrome is characterized by central diabetes Insipidus, diabetes mellitus, optic atrophy and sensorineural deafness.