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Disease Profile

Witkop 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)

Tooth and nail syndrome; TNS; Dysplasia of nails with hypodontia;


Congenital and Genetic Diseases; Mouth Diseases; Skin Diseases


The following summary is from Orphanet, a European reference portal for information on rare diseases and orphan drugs.

Orpha Number: 2228

Hypodontia-nail dysplasia syndrome is a form of ectodermal dysplasia.

Its incidence has been estimated at around 1-2 in 10,000.

Clinical description
The primary teeth are usually normal but the permanent teeth often fail to erupt. The mandibular incisors, second molars, and maxillary canines are frequently absent and the crowns may be small and conical. Lip eversion may be present. Nails are usually small, thin and brittle with longitudinal ridges, pitting and koilonychias. Congenital absence of the nail plate has also been reported. Toenails are usually more severely affected than fingernails. Sweat glands, heat tolerance and hair are normal, although fine hair has been described in some cases.

The syndrome is caused by a mutation in the MSX1 gene (4p16.1).

Diagnostic methods
Diagnosis is usually made during mid-childhood when persistence of the primary dentition becomes apparent, but the syndrome may be difficult to diagnose as the nail defects may be mild.

Differential diagnosis
The differential diagnosis should include other forms of ectodermal dysplasia, in particular hypohidrotic ectodermal dysplasia (see these terms).

Genetic counseling
Transmission is autosomal dominant.

Management and treatment
There is no specific treatment but oral health care and dental management are recommended.

The prognosis is good. The nail defects usually become less apparent with age and the nails often appear normal by adulthood.

Visit the Orphanet disease page for more resources.


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
Agenesis of permanent teeth
Failure of development of permanent teeth
Missing teeth

[ more ]

Conical tooth
Cone shaped tooth
Shark tooth

[ more ]

Delayed eruption of teeth
Delayed eruption
Delayed teeth eruption
Delayed tooth eruption
Eruption, delayed
Late eruption of teeth
Late tooth eruption

[ more ]

Fragile nails
Brittle nails
Failure of development of between one and six teeth
Hypoplastic fingernail
Small fingernail
Underdeveloped fingernail

[ more ]

Hypoplastic toenails
Underdeveloped toenails
Ridged fingernail
Longitudinally grooved fingernails
Thin toenail
30%-79% of people have these symptoms
Everted lower lip vermilion
Drooping lower lip
Outward turned lower lip

[ more ]

Fine hair
Fine hair shaft
Fine hair texture
Thin hair shaft
Thin hair texture

[ more ]

5%-29% of people have these symptoms
Polycystic ovaries
Percent of people who have these symptoms is not available through HPO
Autosomal dominant inheritance
Concave nail
Spoon-shaped nails
Microdontia of primary teeth
Decreased width of baby teeth
Decreased width of milk teeth

[ more ]

Nail pits
Nail pitting
Pitted nails

[ more ]

Ridged nail
Grooved nails
Nail ridging

[ more ]

Small nail
Small nails
Sparse hair

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.

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 Witkop syndrome. Click on the link to view a sample search on this topic.