Which are the causes of Tooth and Nail Syndrome?

Tooth and Nail Syndrome, also known as Ankyloblepharon-Ectodermal Defects-Cleft Lip/Palate (AEC) Syndrome, is a rare genetic disorder that affects the development of various structures in the body. It is primarily caused by mutations in the TP63 gene, which plays a crucial role in the formation of skin, hair, nails, and teeth.

The TP63 gene provides instructions for producing a protein called p63, which is essential for the normal development of ectodermal tissues. Ectodermal tissues are responsible for forming the outer layer of the skin, sweat glands, hair follicles, nails, and tooth enamel. Mutations in the TP63 gene can disrupt the normal functioning of p63, leading to the characteristic features of Tooth and Nail Syndrome.

1. Dental abnormalities: One of the hallmark features of Tooth and Nail Syndrome is the presence of severe dental abnormalities. Affected individuals may have missing teeth (hypodontia), malformed teeth, or teeth that are small and pointed. The tooth enamel may also be thin, making the teeth more susceptible to decay and damage.

2. Nail abnormalities: Another prominent feature of the syndrome is nail abnormalities. The nails may be thin, brittle, and easily breakable. They may also be absent or abnormally shaped. These nail abnormalities can significantly impact the appearance and function of the hands and feet.

3. Skin and hair abnormalities: Individuals with Tooth and Nail Syndrome may have thin, dry, and fragile skin. They may also experience excessive sweating or reduced sweating due to the abnormal sweat gland development. Hair abnormalities can include sparse hair growth, thin hair, or even complete hair loss (alopecia).

4. Cleft lip/palate: Some individuals with Tooth and Nail Syndrome may have a cleft lip and/or cleft palate. These occur when the tissues that form the lip and palate do not fuse properly during fetal development.

5. Other features: Additional features of the syndrome may include eye abnormalities, such as ankyloblepharon (fusion of the eyelids), which can cause vision problems. Some individuals may also have hearing loss or abnormalities in the urinary tract.

Tooth and Nail Syndrome is inherited in an autosomal dominant manner, which means that an affected individual has a 50% chance of passing the condition on to each of their children. Genetic counseling and testing can help determine the risk of recurrence in families with a history of the syndrome.

While there is currently no cure for Tooth and Nail Syndrome, treatment focuses on managing the specific symptoms and improving quality of life. This may involve dental interventions, such as orthodontic treatment or dental implants, to address the dental abnormalities. Supportive therapies, such as moisturizers for the skin and prosthetic devices for nails, can also be beneficial.