The symptoms of<unk>  can be divided into those related to optic nerve underdevelopment, pituitary hormone abnormalities, or mid-line brain abnormalities. Symptoms may vary greatly in their severity. Optic nerve underdevelopment About one quarter of people with<unk>  have significant visual impairment in one or both eyes, as a result of optic nerve underdevelopment. Developmental delays are more common in children with bilateral optic nerve hypoplasia than those with unilateral optic nerve hypoplasia.Bilateral optic nerve hypoplasia is also associated with a more severe disease course. There may be nystagmus (involuntary eye movements, often side-to-side).In cases of bilateral optic nerve hypoplasia this can usually be detected within the first three months of life. It may be followed by strabismus developing in the first year. Pituitary hormone abnormalities Underdevelopment of the pituitary gland in<unk>  leads to hypopituitarism, most commonly in the form of growth hormone deficiency. In severe cases Panhypopituitarism may occur. Mid-line brain abnormalities In<unk>  mid-line brain structures, such as the corpus callosum and the<unk> m pellucidum may fail to develop normally, leading to neurological problems such as seizures or developmental delay. Patients with seizures are more likely to show additional neurological abnormalities such as cortical<unk> , polymicrogyria and schizencephaly. Such abnormalities are always identified when spastic quadriplegia is present. Neurological symptoms are typically considered late onset manifestations of<unk> . Common initial presentations include epilepsy, development delays and limb weakness. Intellectual abilities vary widely from normal to severe intellectual disability. Early studies indicated intellectual disability occurs in 71% of cases, cerebral palsy occurs in 57%, and behavioral problems occur in 20% but further research has indicated that these symptoms may be less common and caused by additional neurological abnormalities.
Septo-optic dysplasia
Optic nerve hypoplasia
Cystic eyeball
Vibroacoustic disease
Post-lingual deafness
Leber congenital amaurosis
Labyrinthine fistula
Congenital stationary night blindness