Norrie disease is a rare X-linked recessive genetic disorder that primarily affects the eyes and almost always leads to blindness.

[1][2] Norrie disease manifests with vision impairment either at birth, or within a few weeks of life, following an ocular event like retinal detachment and is progressive through childhood and adolescence.

[3] Patients with Norrie disease may develop cataracts, leukocoria (where the pupils appear white when light is shone on them), along with other developmental issues in the eye, such as shrinking of the globe and the wasting away of the iris.

[2] In addition to the congenital ocular symptoms, the majority of individuals afflicted by this disease develop progressive hearing loss caused by vascular abnormalities in the cochlea.

[4][5] Roughly 30-50 percent of those affected by the disease might encounter cognitive challenges, learning difficulties, incoordination of movements or behavioral abnormalities.

Initial characteristics are usually identified at birth or in early infancy, with parents often noticing abnormal eye features or that their child fails to show a response to light.

[2][13] However, an affected baby may have a normally sized eye globe and unremarkable iris, anterior chamber, cornea and intraocular pressure.

[5] The slowly progressing hearing loss is more problematic to adjust to than the congenital blindness for most people with Norrie disease.

[21] Norrie disease is a rare genetic disorder caused by mutations in the NDP gene, located on Xp11.4 (GeneID: 4693).

However, there have been a few rare cases where females have shown symptoms associated with Norrie disease such as retinal abnormalities and mild hearing loss.

In this latter case, carrier females with one mutated NDP allele could have a higher proportion of defective norrin being expressed, leading to the presentation of symptoms of Norrie disease.

The role of norrin in the specialization of retinal cells for their unique sensory function is impeded by the mutation of NDP.

On the other hand, if certain structurally important amino acids are changed (e.g. the cysteines forming the putative cystine knot), the clinical outcome has been shown to be more serious.

[26] In utero diagnosis has been reported to include genetic testing by amniocentesis and ultrasonography to examine fetal eyes.

[26][27] Ocular, auditory and behavioral management are the most common areas of intervention and treatment for patients with Norrie disease.

For ocular (eye) management, often patients already have complete retinal detachment at birth, or by the time of diagnosis, so surgical intervention is often not offered.

[2][27][28] Surgery may also be used to treat increased intraocular pressure and in rare cases enucleation (removal) of the eye is considered to control pain.

[2] A high proportion (85–90%) of individuals with Norrie disease experience progressive hearing loss in their second decade of life.

[2] Furthermore, training of teachers and school counselors on how to best support children with vision and hearing impairment can be extremely beneficial.

[2] More recently, the use of dual sensory clinics has been proposed to provide improved care to patients living with conditions such as Norrie disease.

For example, Great Ormond Street Hospital (GOSH), London are building a new Sight and Sound center, with the aim of improving the patient experience for individuals with conditions such as Norrie disease.

[29] The benefits of dual sensory clinics include improved communication between the different health care professionals (HCPs) involved in management of Norrie disease (e.g. ophthalmologists and audiologists) as well as allowing more consistent training of staff on best practices for managing and interacting with individuals with sensory impairment.

For example, a number of Norrie disease patients have been reported to experience transient depression correlating with the onset of hearing loss.

For example, research is taking place at Great Ormond Street Institute of Child Health, University College London (UCL GOSICH) to study the developmental changes in the ear and eye in Norrie disease, with the hope to understand how to improve current treatment strategies.

[30] The group at UCL GOSICH is focusing particularly on the hearing loss aspect of the disease, and whether it might be possible to treat by gene therapy.

A histologic examination showed a hemorrhagic necrotic mass in the posterior chamber, surrounded by undifferentiated (immature, undeveloped) glial tissue.

After Warburg researched literature under various medical categories, she discovered 48 similar cases which she believed were caused by this disease as well.