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Disease Profile

Nance-Horan syndrome

Prevalence estimates on Rare Medical Network websites are calculated based on data available from numerous sources, including US and European government statistics, the NIH, Orphanet, and published epidemiologic studies. Rare disease population data is recognized to be highly variable, and based on a wide variety of source data and methodologies, so the prevalence data on this site should be assumed to be estimated and cannot be considered to be absolutely correct.


US Estimated

Europe Estimated

Age of onset





Autosomal dominant A pathogenic variant in only one gene copy in each cell is sufficient to cause an autosomal dominant disease.


Autosomal recessive Pathogenic variants in both copies of each gene of the chromosome are needed to cause an autosomal recessive disease and observe the mutant phenotype.


dominant X-linked dominant inheritance, sometimes referred to as X-linked dominance, is a mode of genetic inheritance by which a dominant gene is carried on the X chromosome.


recessive Pathogenic variants in both copies of a gene on the X chromosome cause an X-linked recessive disorder.


Mitochondrial or multigenic Mitochondrial genetic disorders can be caused by changes (mutations) in either the mitochondrial DNA or nuclear DNA that lead to dysfunction of the mitochondria and inadequate production of energy.


Multigenic or multifactor Inheritance involving many factors, of which at least one is genetic but none is of overwhelming importance, as in the causation of a disease by multiple genetic and environmental factors.


Not applicable


Other names (AKA)

Cataract dental syndrome; Cataract X-linked with Hutchinsonian teeth; Mesiodens cataract syndrome


Congenital and Genetic Diseases; Eye diseases; Mouth Diseases;


Nance-Horan syndrome is a rare genetic disorder that may be evident at birth. It is characterized by teeth abnormalities and cataracts, resulting in poor vision. Additional eye abnormalities are also often present, including a very small cornea and nystagmus. In some cases, the condition may also be associated with physical abnormalities and/or intellectual disability. The range and severity of symptoms may vary greatly from one person to another, even among affected members of the same family. Nance-Horan syndrome is caused by a mutation in the NHS gene and is inherited as an X-linked dominant trait, which means that both males and females can be affected, but males often have more severe symptoms.The treatment is directed toward the specific symptoms that are apparent in the individual.[1][2]


The main features of Nance-Horan syndrome include congenital cataracts, dental abnormalities, distinctive facial features, and in some cases, intellectual disability.[1]

In affected males, the primary physical characteristic is the presence of dense clouding of the lens (cornea) of both eyes at birth (congenital bilateral cataracts). The cataracts usually result in blurred vision and severely decreased clearness or clarity of vision (visual acuity). Vision loss can potentially be profound. Males with Nance-Horan syndrome may have additional eye abnormalities, including a very small cornea (microcornea); involuntary movements of the eyes (nystagmus), and/or misalignment of the eyes (strabismus). In some cases, the entire eye may be abnormally small (microphthalmia) and/or the upper eyelid may droop (ptosis).[1]

Males with Nance-Horan syndrome may also have several dental abnormalities such as unusually shaped, extra (supernumerary) teeth, absence of some teeth (dental agenesis), impacted teeth or unusually wide spaces (diastema) between some of the teeth. The front teeth, or incisors, are usually tapered and 'screwdriver-shaped'. The teeth in the back of the mouth may be cone-shaped, rounded, or cylindrical.[1]

In many males with Nance-Horan syndrome, other physical findings may also occur. Distinctive facial features may be present, but may be subtle. The ears may be flared forward and unusually prominent. Affected males may also have a large, prominent nose with a high, narrow nasal bridge, a narrow prominent jaw, and sometimes a long, narrow face.[1]

Some males with Nance-Horan syndrome may also experience delays the skills necessary for coordinating muscular and mental activity. In addition, some reports suggest that approximately 20 to 30 percent of affected males may have varying levels of intellectual disability, which is usually mild to moderate; but in some cases can be severe.[1]

Females who carry a single copy of the mutation in the NHS gene may develop some symptoms of the disorder. However, symptoms are usually milder and more variable than those seen in males. Affected females may have abnormally small corneas (microcornea) and/or some clouding of the cornea. Vision may be normal, or there may be slightly decreased visual acuity. Without appropriate treatment, clouding of the cornea can lead to total cataracts later in life. Females often have some dental abnormalities, such as abnormally-shaped front teeth and/or unusually wide spaces between some of the teeth. Affected females usually do not develop intellectual disability.[1]

This table lists symptoms that people with this disease may have. For most diseases, symptoms will vary from person to person. People with the same disease may not have all the symptoms listed. This information comes from a database called the Human Phenotype Ontology (HPO) . The HPO collects information on symptoms that have been described in medical resources. The HPO is updated regularly. Use the HPO ID to access more in-depth information about a symptom.

Medical Terms Other Names
Learn More:
80%-99% of people have these symptoms
Clouding of the lens of the eye
Cloudy lens

[ more ]

Long face
Elongation of face
Increased height of face
Increased length of face
Vertical elongation of face
Vertical enlargement of face
Vertical overgrowth of face

[ more ]

Mandibular prognathia
Big lower jaw
Increased projection of lower jaw
Increased size of lower jaw
Large lower jaw
Prominent chin
Prominent lower jaw

[ more ]

Cornea of eye less than 10mm in diameter
Involuntary, rapid, rhythmic eye movements
Prominent nasal bridge
Elevated nasal bridge
High nasal bridge
Prominent bridge of nose
Prominent nasal root
Protruding bridge of nose
Protruding nasal bridge

[ more ]

Prominent nose
Big nose
Disproportionately large nose
Increased nasal size
Increased size of nose
Large nose
Pronounced nose

[ more ]

Visual loss
Loss of vision
Vision loss

[ more ]

30%-79% of people have these symptoms
Increased number of teeth
Extra teeth
Increased tooth count
Supplemental teeth

[ more ]

Intellectual disability
Mental deficiency
Mental retardation
Mental retardation, nonspecific

[ more ]

Protruding ear
Prominent ear
Prominent ears

[ more ]

Short metacarpal
Shortened long bone of hand
Squint eyes

[ more ]

5%-29% of people have these symptoms
Behavioral abnormality
Behavioral changes
Behavioral disorders
Behavioral disturbances
Behavioral problems
Behavioral/psychiatric abnormalities
Behavioural/Psychiatric abnormality
Psychiatric disorders
Psychiatric disturbances

[ more ]

Abnormally small eyeball
Retinal detachment
Detached retina
1%-4% of people have these symptoms
Intellectual disability, moderate
IQ between 34 and 49
Mulberry molar
Screwdriver-shaped incisors
Screwdriver shaped front teeth
Percent of people who have these symptoms is not available through HPO
Broad finger
Broad fingers
Wide fingers

[ more ]

Developmental cataract
Clouding of the lens of the eye at birth
Gap between teeth
Large ears
Narrow face
Decreased breadth of face
Decreased width of face

[ more ]

Posterior Y-sutural cataract
Short phalanx of finger
Short finger bones
Supernumerary maxillary incisor
Extra upper front tooth
X-linked dominant inheritance


Nance-Horan syndrome is caused by a mutation in the NHS gene, which is located on the X chromosome.[2] Some patients have losses (deletions) of part of the chromosome X short arm (p) within the region involving the NHS gene and other genes that are located in this region. These patients may have more problems and the problems may be more serious.[3]


Making a diagnosis for a genetic or rare disease can often be challenging. Healthcare professionals typically look at a person’s medical history, symptoms, physical exam, and laboratory test results in order to make a diagnosis. The following resources provide information relating to diagnosis and testing for this condition. If you have questions about getting a diagnosis, you should contact a healthcare professional.

Testing Resources

  • The Genetic Testing Registry (GTR) provides information about the genetic tests for this condition. The intended audience for the GTR is health care providers and researchers. Patients and consumers with specific questions about a genetic test should contact a health care provider or a genetics professional.


    Support and advocacy groups can help you connect with other patients and families, and they can provide valuable services. Many develop patient-centered information and are the driving force behind research for better treatments and possible cures. They can direct you to research, resources, and services. Many organizations also have experts who serve as medical advisors or provide lists of doctors/clinics. Visit the group’s website or contact them to learn about the services they offer. Inclusion on this list is not an endorsement by GARD.

    Organizations Supporting this Disease

      Organizations Providing General Support

        Learn more

        These resources provide more information about this condition or associated symptoms. The in-depth resources contain medical and scientific language that may be hard to understand. You may want to review these resources with a medical professional.

        Where to Start

        • The National Organization for Rare Disorders (NORD) has a report for patients and families about this condition. NORD is a patient advocacy organization for individuals with rare diseases and the organizations that serve them.

          In-Depth Information

          • The Monarch Initiative brings together data about this condition from humans and other species to help physicians and biomedical researchers. Monarch’s tools are designed to make it easier to compare the signs and symptoms (phenotypes) of different diseases and discover common features. This initiative is a collaboration between several academic institutions across the world and is funded by the National Institutes of Health. Visit the website to explore the biology of this condition.
          • Online Mendelian Inheritance in Man (OMIM) is a catalog of human genes and genetic disorders. Each entry has a summary of related medical articles. It is meant for health care professionals and researchers. OMIM is maintained by Johns Hopkins University School of Medicine. 
          • Orphanet is a European reference portal for information on rare diseases and orphan drugs. Access to this database is free of charge.
          • PubMed is a searchable database of medical literature and lists journal articles that discuss Nance-Horan syndrome. Click on the link to view a sample search on this topic.


            1. Nance-Horan Syndrome. National Organization for Rare Disorders (NORD). 2014; https://www.rarediseases.org/rare-disease-information/rare-diseases/byID/1055/viewAbstract. Accessed 9/15/2015.
            2. Nance-Horan syndrome. Orphanet. September 2007; https://www.orpha.net/consor/cgi-bin/Disease_Search.php?lng=EN&data_id=931. Accessed 9/15/2015.
            3. Nance-Horan syndrome. OMIM. December 5, 2015; https://omim.org/entry/302350. Accessed 9/15/2015.

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