Synonyms

  • Ectodermal dysplasia 14, hair/tooth type with or without hypohidrosis
  • Selective tooth agenesis

TSPEAR is a Rare Genetic Condition Characterized by

  • Missing teeth (hypodontia) – in some people, this is the main symptom
  • Thin scalp hair (scalp hypotrichosis)
  • Normal sweating

Teeth

  • Hypodontia
  • Oligodontia
  • Conical teeth

People affected by TSPEAR-related ectodermal dysplasia often have missing teeth (hypodontia), and their teeth can be shaped differently than other people’s (conical teeth). Some people have no teeth at all. If the only symptom is missing teeth, it is called isolated tooth agenesis. 

Hair

  • Sparse hair
  • Hypotrichosis
  • Alopecia

Sparse scalp hair (scalp hypotrichosis) is typical. This is often more noticeable towards the front hairline. Some people also have sparse eyebrows and eyelashes. Body hair on the arms and legs can be sparse or absent. 

Sweat Glands

  • Reduced sweating has been seen in some people (hypohidrosis)

Nails

  • Nail dysplasia in some

Other

  • Some individuals have unusual facial features.
  • Development and learning are normal.

Different facial features can include down slanting eyes, a broad forehead, a broad nose, thick lips, and low set ears. There are no other major health or developmental concerns reported.  

Older studies first showed that changes in the TSPEAR gene could cause hearing loss. However, as more people with changes in this gene have been found, newer research shows that most people have normal hearing. It is thought that there could be additional genetic factors involved in the people who have changes in TSPEAR and hearing loss. 

This condition is caused by changes in the TSPEAR gene. This gene plays an important role in telling the body how to develop teeth and hair. When it is not working correctly, people can show symptoms.

A diagnosis of TSPEAR-related ectodermal dysplasia is made through genetic testing. A clinical exam can identify many of the characteristic symptoms, but genetic testing is needed for the most accurate diagnosis. 

Genetic Testing

Molecular genetic testing is available for TSPEAR-related ectodermal dysplasia. The TSPEAR gene is included on many ectodermal dysplasia gene panels.

TSPEAR-related ectodermal dysplasia is an autosomal recessive condition. This means that both copies of the TSPEAR gene need to have a change for someone to have it. Parents of people with TSPEAR-related ectodermal dysplasia are carriers for the condition. This means that one of their two copies of this gene has a change while the other does not have any changes. 

Couples who have an affected child have a 25% chance of having another child each time they are pregnant. 

People with TSPEAR-related ectodermal dysplasia can only have a child with this condition if their partner is also affected with or a carrier for this condition.

Affected Population

TSPEAR-related ectodermal dysplasia affects males and females in equal numbers. It was originally found in people with Middle Eastern ancestry, but people of any ethnic background can be affected. The exact incidence and prevalence of the disorder in the general population are unknown. 

Learn more information about TSPEAR-related ectodermal dysplasia at  Online Mendelia Inheritance in Man.

Read Family Perspective

Discover A Newer Syndrome: T-SPEAR-related Ectodermal Dysplasia