<unk>  may be found in isolation or in conjunction with myriad functional and anatomic abnormalities of the central<unk> us system. Nearly 80% of those affected with<unk>  will experience hypothalamic dysfunction and/or impaired development of the brain, regardless of MRI findings or severity of<unk> . Vision<unk>  can be unilateral (in one eye) or bilateral (in both eyes), although it presents most often bilaterally (80%). Because the unilateral cases tend to have better vision, they are typically diagnosed at a later age than those with bilateral<unk> . Visual acuity can range from no light perception to near-normal vision. Children diagnosed with<unk>  generally present with vision problems which include nystagmus (involuntary movement of the eyes), which tends to develop at 1 to 3 months and/or strabismus (inability to align both eyes simultaneously), manifested during the first year of life. The majority of children affected experience improvement in vision during the first few years of life, though the reason for this occurrence is unknown. There have been no reported cases of decline in vision due to<unk> . Neuroradiographic abnormalities Estimates of cerebral malformations vary from 39% to 90% of children with<unk> . Abnormalities evident via neuroradiography can include agenesis (absence) or<unk>  of the corpus callosum, absence or incomplete development of the septum pellucidum, malformations of the pituitary gland, schizencephaly, cortical heterotopia, white matter<unk> , pachygyria, and holoprosencephaly.<unk>  of the corpus callosum, often in conjunction with other major malformations, is significantly associated with poor and delayed developmental outcome.<unk>  is often referred to as septo-optic dysplasia, a term that refers to agenesis of the septum pellucidum. It is now clear that the absence of the septum pellucidum does not correlate with the associated symptoms of<unk> . Hypothalamic dysfunction Dysfunction of the hypothalamus results in loss of regulation over behavior and function of the pituitary gland (master gland). Hypopituitarism is present in 75% to 80% of patients with<unk> . The anterior pituitary gland contributes to growth, metabolism, and sexual development. The most common pituitary endocrinopathies are growth hormone (GH) deficiency (70%), hypothyroidism (43%), adrenal insufficiency (27%), and diabetes insipidus (5%). Absence of GH may often be indicated by short stature, although this is not always the case. Other indicators of GH deficiency may include hypoglycemic events (including seizures), prolonged jaundice, micropenis in boys, and delayed dentition. Testing for GH may involve blood tests (IGF-1 and IGFBP-3), growth hormone stimulation test, or bone age x-ray of the hand or wrist (or body for children younger than 2 years). A poorly functioning pituitary gland may also cause a lack of thyroid hormone, leading to central hypothyroidism. Thyroid hormone is critical for growth and brain development, especially during the first few weeks to months of life. Children with untreated hypothyroidism are at high risk of mental retardation; thus, early detection is crucial. Central hypothyroidism can be diagnosed by a low or normal thyroid-stimulating hormone (TSH) in the presence of a low level of free T4. Free T-4 should be checked annually for at least four years. Cortisol is made in times of stress. Approximately one-quarter of patients with<unk>  have adrenal insufficiency, meaning they do not produce enough cortisol on a daily basis or in stressful situations. Imbalances in sex hormone may result in a delay in sexual development (puberty) or precocious puberty. Sex hormones may be tested from birth to 6 months of age (during a mini-puberty). Hyperprolactinemia (an excess of prolactin) often occurs in conjunction with<unk>  and indicates either dysfunction of the hypothalamus or a disconnect between the hypothalamus and pituitary gland. Hyperprolactinemia often correlates with development of obesity in children with<unk> . The posterior pituitary gland produces anti-diuretic hormone (ADH), which controls outflow of water from the body by urine. ADH deficiency, also known as diabetes insipidus (DI), results in dehydration and high sodium levels in the body from excessive urination. Testing for DI involves blood and urine testing, including water deprivation tests, to determine ADH creation levels by the body. DI may be treated with a medication called desmopressin acetate (DDAVP). Oxytocin is also produced in the posterior pituitary gland. Though best known for its role in childbirth and lactation, oxytocin has also been found to have a role in human bonding, increase in trust, and decrease in fear. Hypothalamic dysfunction may also result in problems with feeding, sleep, and body temperature regulation. Feeding behaviors in children with<unk>  often include hyperphagia (overeating), resulting in obesity; or hypophagia (reduced food intake) with or without weight loss. Children also frequently experience aversion to specific textures of food. Disturbance of circadian sleep rhythm, resulting in abnormal sleep-wake cycles, is noted in one-third of children with<unk> . This disturbance could result in behavioral problems and disruption of family life. Development More than 70% of children with<unk>  experience developmental delay, ranging from isolated focal defects to delay in all areas of development (global delay). Motor delay is most common (75%) and communication delay is least common (44%). Predictors of significantly delayed development include<unk>  or agenesis of the corpus callosum and hypothyroidism. The absence of the septum pellucidum does not predict developmental delay. Delays may occur in unilateral (39%) as well as bilateral (78%) cases.
Optic nerve hypoplasia
Septo-optic dysplasia
Macular hypoplasia
Cystic eyeball
Retinal dysplasia
Congenital cataract
Vitreous bulge
Post-lingual deafness