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Nance-Horan syndrome

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Other Names:
Cataract dental syndrome; Cataract X-linked with Hutchinsonian teeth; Mesiodens cataract syndrome
Categories:
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]
Last updated: 9/15/2015
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]
Last updated: 8/22/2011

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.

Showing of 30 |
Medical Terms Other Names
Learn More:
HPO ID
80%-99% of people have these symptoms
Cataract
Clouding of the lens of the eye
Cloudy lens
[ more ] 		0000518
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 ] 		0000276
Mandibular prognathia
Big lower jaw
Increased projection of lower jaw
Increased size of lower jaw
Large lower jaw
Prominent chin
Prominent lower jaw
[ more ] 		0000303
Microcornea
Cornea of eye less than 10mm in diameter
0000482
Nystagmus
Involuntary, rapid, rhythmic eye movements
0000639
Prominent nasal bridge
Elevated nasal bridge
High nasal bridge
Prominent bridge of nose
Prominent nasal root
Protruding bridge of nose
Protruding nasal bridge
[ more ] 		0000426
Prominent nose
Big nose
Disproportionately large nose
Increased nasal size
Increased size of nose
Large nose
Pronounced nose
[ more ] 		0000448
Visual loss
Loss of vision
Vision loss
[ more ] 		0000572
30%-79% of people have these symptoms
Increased number of teeth
Extra teeth
Increased tooth count
Supplemental teeth
[ more ] 		0011069
Intellectual disability
Mental deficiency
Mental retardation
Mental retardation, nonspecific
Mental-retardation
[ more ] 		0001249
Protruding ear
Prominent ear
Prominent ears
[ more ] 		0000411
Short metacarpal
Shortened long bone of hand
0010049
Strabismus
Cross-eyed
Squint
Squint eyes
[ more ] 		0000486
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 ] 		0000708
Glaucoma 0000501
Microphthalmia
Abnormally small eyeball
0000568
Retinal detachment
Detached retina
0000541
1%-4% of people have these symptoms
Intellectual disability, moderate
IQ between 34 and 49
0002342
Mulberry molar 0011092
Screwdriver-shaped incisors
Screwdriver shaped front teeth
0006346
Percent of people who have these symptoms is not available through HPO
Autism 0000717
Broad finger
Broad fingers
Wide fingers
[ more ] 		0001500
Developmental cataract
Clouding of the lens of the eye at birth
0000519
Diastema
Gap between teeth
0000699
Macrotia
Large ears
0000400
Narrow face
Decreased breadth of face
Decreased width of face
[ more ] 		0000275
Posterior Y-sutural cataract 0008031
Short phalanx of finger
Short finger bones
0009803
Supernumerary maxillary incisor
Extra upper front tooth
0006332
X-linked dominant inheritance 0001423
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Last updated: 7/1/2020
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]
Last updated: 8/22/2011
Nance-Horan syndrome is inherited as an X-linked dominant trait. In X-linked dominant inheritance, both males and females can be affected by a condition. However, affected males tend to have more severe features than females.[1]

X-linked conditions result from mutations of a gene located on an X chromosome. Females have two X chromosomes, but males have one X chromosome and one Y chromosome. In females, disease traits resulting from the abnormal copy of a gene on one X chromosome can be 'masked' by the normal copy of the gene on the other X chromosome. Because only one functioning X chromosome is required in males and females, one of the X chromosomes in each cell of a female is essentially 'turned off,' usually in a random pattern (X chromosome inactivation). Therefore, if the X chromosome with the gene mutation is activated in some cells, female carriers may have some mild features of the disorder. However, since males only have one X chromosome, they will likely fully express a condition if they inherit a gene mutation that is located on the X chromosome.[1]
Last updated: 8/22/2011

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.

If you need medical advice, you can look for doctors or other healthcare professionals who have experience with this disease. You may find these specialists through advocacy organizations, clinical trials, or articles published in medical journals. You may also want to contact a university or tertiary medical center in your area, because these centers tend to see more complex cases and have the latest technology and treatments.

If you can’t find a specialist in your local area, try contacting national or international specialists. They may be able to refer you to someone they know through conferences or research efforts. Some specialists may be willing to consult with you or your local doctors over the phone or by email if you can't travel to them for care.

You can find more tips in our guide, How to Find a Disease Specialist. We also encourage you to explore the rest of this page to find resources that can help you find specialists.

Healthcare Resources

Related diseases are conditions that have similar signs and symptoms. A health care provider may consider these conditions in the table below when making a diagnosis. Please note that the table may not include all the possible conditions related to this disease.

Conditions with similar signs and symptoms from Orphanet
Differential diagnosis includes: X-linked microphthalmia, Lenz syndrome, Oculo-facio-cardio-dental (OFCD) syndrome, and Oculo-cerebro-renal (Lowe) syndrome (see these terms).
Visit the Orphanet disease page for more information.

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

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.

Questions sent to GARD may be posted here if the information could be helpful to others. We remove all identifying information when posting a question to protect your privacy. If you do not want your question posted, please let us know. Submit a new question

  • My nephew was diagnosed with Nance-Horan syndrome. He was born with cataracts, supernumerary teeth, and facial dysmorphism. He doesn't have intellectual disabilities. My sister is the carrier and she has some of the characteristics; but much less severe than her son. No other family members have features of the syndrome. Is it possible that the genetic defect started with her? And what are the chances of my sister having a child without the defect? Is it possible to be a carrier and not show any outward signs of the syndrome? See answer


  1. Nance-Horan Syndrome. National Organization for Rare Disorders (NORD). 2014; http://www.rarediseases.org/rare-disease-information/rare-diseases/byID/1055/viewAbstract. Accessed 9/15/2015.
  2. Nance-Horan syndrome. Orphanet. September 2007; http://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; http://omim.org/entry/302350. Accessed 9/15/2015.