Which are the symptoms of Nance-Horan Syndrome?

Nance-Horan Syndrome (NHS) is a rare genetic disorder that primarily affects the development of the eyes, teeth, and facial features. It is an X-linked condition, meaning it predominantly affects males, although females can also be carriers of the gene mutation.

Eye-related symptoms:

• Congenital cataracts: Cataracts are present at birth or develop shortly after. They cause clouding of the lens, leading to blurred vision or even blindness if left untreated.


• Microphthalmia: This refers to abnormally small eyes, which may be underdeveloped and have reduced visual acuity.


• Strabismus: Also known as crossed eyes, strabismus is a condition where the eyes do not align properly, causing one or both eyes to turn inward, outward, upward, or downward.


• Optic nerve hypoplasia: The optic nerve, responsible for transmitting visual information from the eye to the brain, is underdeveloped in individuals with NHS. This can result in vision problems.


• Glaucoma: Some individuals with NHS may develop increased pressure within the eye, leading to optic nerve damage and potential vision loss.

Dental symptoms:

• Delayed tooth eruption: Teeth may emerge later than usual or fail to erupt at all.


• Supernumerary teeth: Extra teeth may develop, causing overcrowding and misalignment.


• Small or pointed teeth: Teeth may be smaller in size or have abnormal shapes.


• Missing teeth: Some individuals with NHS may have congenitally missing teeth, particularly the upper lateral incisors.

Facial features:

• Long face: Individuals with NHS may have a narrow and elongated face.


• Prominent nose: The nose may appear more pronounced or have a bulbous tip.


• Anteverted nostrils: Nostrils may be positioned more forward than usual.


• Elongated philtrum: The groove between the nose and upper lip may be longer than average.


• Wide nasal bridge: The bridge of the nose may be broader than typical.

It is important to note that the severity and combination of symptoms can vary among individuals with NHS. Some individuals may only exhibit a few of the mentioned symptoms, while others may experience a broader range of manifestations.

Diagnosis of Nance-Horan Syndrome is typically based on clinical evaluation, family history, and genetic testing. Genetic counseling is recommended for affected individuals and their families to understand the inheritance pattern and potential risks.

Treatment for NHS is primarily focused on managing the specific symptoms and may involve surgical intervention for cataracts, glaucoma, or dental issues. Early intervention and regular follow-up with healthcare professionals specializing in ophthalmology and dentistry are crucial to optimize visual and dental outcomes.