What is Tooth and nail syndrome?

Tooth and nail syndrome (TNS) is a rare genetic disorder that belongs to a group of diseases known as ectodermal dysplasia, which group consists of more than 100 separate recognized syndromes.

Ectodermal dysplasias typically affect the teeth, nails, hair, and/or skin. Tooth and nail syndrome is characterized by absence and/or malformation of certain primary and secondary teeth occurring in association with improper development of the nails, particularly the toenails.

How common is Tooth and nail syndrome?

Tooth and nail syndrome affects males and females in equal numbers. Since the disorder was originally described in the medical literature in 1965 (C.J. Witkop), over 30 cases have been reported, with many such cases occurring within several families (kindreds). According to the medical literature, it is estimated that one to two in every 10,000 individuals may be affected by tooth and nail syndrome. Some researchers have reported that the disorder appears to be prevalent among Dutch Mennonites of Canada. Please discuss with your doctor for further information.


What are the symptoms of Tooth and nail syndrome?

In some infants with tooth and nail syndrome, certain primary teeth may be absent or abnormally conical in shape (coniform).

In addition, in most affected children, several secondary teeth are also absent and/or malformed. The secondary teeth most often absent include:

  • The lower front teeth (mandibular incisors)
  • The teeth next to the incisors in the upper jaw (maxillary canines)
  • The upper and lower molars

The upper portions (crowns) of certain permanant teeth may be cone shaped and, in some cases, the teeth may be widely spaced.

Many infants and children with the disorder appear to have a “pouting” or outwardly turned lower lip (everted) due to absence of certain primary and/or secondary teeth.

Individuals with tooth and nail syndrome also have distinctive abnormalities of the toenails and/or fingernails. The nails may be absent at birth and may grow extremely slowly, particularly from infancy to approximately two to three years of age. In addition, when the nails begin to grow, they may be unusually small and underdeveloped (hypoplastic), with distinctive, abnormal hollowing that causes them to appear spoon shaped.

In most individuals with tooth and nail syndrome, the toenails are more severely affected than the fingernails. In some cases, the nails may appear normal in older children and adults with the disorder. However, in other cases, the toenails continue to appear abnormally small and/or spoon shaped.

Some individuals with tooth and nail syndrome have scalp hair that is abnormally thin, fine, and brittle.

There may be some symptoms not listed above. If you have any concerns about a symptom, please consult your doctor.

When should I see my doctor?

If you or your loved one has any signs or symptoms listed above or you have any questions, please consult with your doctor. Everyone’s body acts differently. It is always best to discuss with your doctor what is best for your situation.


What causes Tooth and nail syndrome?

The gene responsible for TNS was identified in 2001 and is termed MSX1. This gene is responsible for production of protein which deals with development of teeth, nails, and skin. A mutation in MSX1 gene results in decreased production of this protein, causing Tooth and nail syndrome.

Risk factors

What increases my risk for Tooth and nail syndrome?

Tooth and nail syndrome follows an autosomal dominant trait meaning that only one copy of the faulty gene is required from any parent for development of this condition. Please consult with your doctor for further information.

Diagnosis & treatment

The information provided is not a substitute for any medical advice. ALWAYS consult with your doctor for more information.

How is Tooth and nail syndrome diagnosed?

In some cases, tooth and nail syndrome may be suspected at birth if one or more toenails and/or fingernails are absent. More commonly, the disorder is detected at approximately four or five years of age, when the absence of certain primary (deciduous) teeth and underdevelopment (hypoplasia) of nails may be noted. Other times, a diagnosis of tooth and nail syndrome may not be confirmed until approximately seven to 15 years of age, when absence and malformation of several secondary (permanent) teeth and nail dysplasia has been verified.

A diagnosis of tooth and nail syndrome is confirmed based upon a thorough clinical evaluation and the identification of characteristic physical findings.

How is Tooth and nail syndrome treated?

The treatment of tooth and nail syndrome is directed toward the specific symptoms and findings that are apparent in each individual. Pediatricians; dental surgeons; dental specialists who diagnose and/or correct misalignment (orthodontists); and/or other health care professionals may work together to ensure a comprehensive approach to treatment.

Treatment may primarily consist of dental restoration. Artificial teeth and/or other devices (prosthetics) may be used to replace absent teeth. In addition, braces, dental surgery, and/or other corrective procedures may be undertaken to correct dental abnormalities.

Genetic counseling is of benefit for affected individuals and their families. Other treatment for this disorder is symptomatic and supportive.

Lifestyle changes & home remedies

What are some lifestyle changes or home remedies that can help me manage Tooth and nail syndrome?

If you have any questions, please consult with your doctor to better understand the best solution for you.

Hello Health Group does not provide medical advice, diagnosis or treatment.


Review Date: February 6, 2018 | Last Modified: February 6, 2018

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