<unk>  results from an abnormality in the development of the embryonic forebrain at 4-6 weeks of pregnancy. There is no known single cause of<unk> , but it is thought that both genetic and environmental factors may be involved. Genetic Rare familial recurrence has been reported, suggesting at least one genetic form (HESX1). Five homozygous and eight heterozygous pathogenic HESX1 mutations have been discovered. Patients with homozygous mutations present with a typical<unk>  phenotype while those with homozygous mutations are mildly effected. In addition to HESX1, mutations in OTX2, SOX2 and PAX6 have been implicated in<unk> . SOX2 mutations in<unk>  patients are associated with severe bilateral ocular anomalies such as microphthalmia and anophthalmia. Additional features associated with SOX2 mutations include developmental delay, oesophageal atresia, short stature and sensorineural hearing loss. Genetic abnormalities are identified in fewer than one percent of patients.
Septo-optic dysplasia
Optic nerve hypoplasia
Cystic eyeball
Vibroacoustic disease
Post-lingual deafness
Leber congenital amaurosis
Labyrinthine fistula
Congenital stationary night blindness