What are the other Names for this Condition? (Also known as/Synonyms)

• Acrodysplasia V
• Giedion Syndrome
• TRPSE (Trichorhinophalangeal Syndrome with Exostoses) 

What is Trichorhinophalangeal Syndrome Type I? (Definition/Background Information)

• Trichorhinophalangeal Syndrome is a rare, genetic disorder characterized by sparse scalp hair, thin nails, pear-shaped broad nose, and cone-shaped epiphyses (the end portion of long bones that is usually rounded) of the middle phalanges of some fingers and toes
• The various types of the condition that has been defined include:
  • Trichorhinophalangeal Syndrome Type I
  • Trichorhinophalangeal Syndrome Type II
  • Trichorhinophalangeal Syndrome Type III

Trichorhinophalangeal Syndrome Type I (TRPS1) is a rare, multisystem, autosomal dominant disorder that is characterized by the following features:

• Typical facial appearances such as:
  • Scarce scalp hair, slow-growing hair, and a high frontal hairline
  • Rarefaction (thinning) of the lateral eyebrows
  • Pear-shaped and rounded nose
  • Prolonged and extended philtrum, thin upper lip
  • Receding chin and protruding ears
  • Abnormally-small jaw
  • Dental anomalies
• Skeletal abnormalities
• Cone-shaped epiphysis (growing ends of the bones) in fingers and toes
• Short stature
• Hip malformations

Trichorhinophalangeal Syndrome Type I is a form of ectodermal dysplasia, a disorder that is derived from prenatal defects of the teeth, hair, nails, and the sweat glands. It is the most common of all the 3 types.

• Trichorhinophalangeal Syndrome Type I is believed to be caused by mutations in the TRPS1 gene, which is located on chromosome 8. It is associated with transcriptional repressor that is responsible for hair development and chondrocyte modulation 

Who gets Trichorhinophalangeal Syndrome Type I? (Age and Sex Distribution)

• The exact incidence of Trichorhinophalangeal Syndrome Type I is not known. But, a few hundred people have been diagnosed with types I, II, and III
• The condition is gender  and age non-specific, but it is manifested at birth
• No racial and ethnic predominance has been observed
• A cluster of individuals with the syndrome are reportedly in Sweden

What are the Risk Factors for Trichorhinophalangeal Syndrome Type I? (Predisposing Factors)

The risk factors associated with Trichorhinophalangeal Syndrome Type I include:

• Positive family history: It is a genetic disorder usually inherited in an autosomal dominant pattern. Hence, genetic factors constitute the main risk factor for this disorder 

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases ones chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.

Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.

What are the Causes of Trichorhinophalangeal Syndrome Type I? (Etiology)

Trichorhinophalangeal Syndrome Type 1 is a genetic disorder, which is commonly inherited in an autosomal dominant pattern.

• It is believed to be caused by mutations in the TRPS1 gene located on chromosome 8
• The TRPS1 gene is responsible for providing instructions for making a protein (zinc finger protein), which helps in regulating the activities of many other genes
• This protein actually interacts with specific regions of DNA and with other proteins and helps to turn genes ‘on and off’
• TRPS1 protein, hence called as transcription factor, plays an important role in controlling the growth of bones and cartilage (a tough and flexible tissue that makes up the skeleton). An alteration or deletion in the TRPS1 gene means that normal bone growth is disrupted
• It is believed that the disturbance caused in the functioning of the TRPS1 gene is the main reason for the short stature, epiphyses abnormalities, and distinctive facial features, which are the characteristic features of Trichorhinophalangeal Syndromes
• In rare cases, an autosomal recessive pattern of inheritance has also been observed

Autosomal dominant: Autosomal dominant conditions are traits or disorders that are present when only one copy of the mutation is inherited on a non-sex chromosome. In these types of conditions, the individual has one normal copy and one mutant copy of the gene. The abnormal gene dominates, masking the effects of the correctly functioning gene. If an individual has an autosomal dominant condition, the chance of passing the abnormal gene on to their offspring is 50%. Children, who do not inherit the abnormal gene, will not develop the condition or pass it on to their offspring. 

What are the Signs and Symptoms of Trichorhinophalangeal Syndrome Type I?

The signs and symptoms of Trichorhinophalangeal Syndrome Type I include:

• Sparse or very little hair in the scalp, slow growth of scalp hair
• Pear-shaped broad nose
• Short and deformed fingers, short toes
• Cone shaped epiphyses in the middle phalanges of the hands
• Short stature
• Dysplasia of the Hip
• Long philtrum (vertical groove between the nose and upper lip), thin upper lip
• Medially thick, laterally thin, or absent eyebrows
• Mild mental retardation, average intelligence

How is Trichorhinophalangeal Syndrome Type I Diagnosed?

The diagnosis of Trichorhinophalangeal Syndrome Type I may involve:

• The diagnosis is based on the clinical examination and skeletal radiology
• After the age of 3 or 4 years, x-rays may show epiphyseal coning (cone-shaped formation of the growing ends of the bones) on the middle joints of the hands and feet
• Genetic testing may also be performed using molecular methods
• If alteration or mutation of the related gene has been identified in the family, fetal diagnosis and embryo diagnosis is also possible
• Genetic counseling at the time of diagnosis should be provided to the family members 

Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.

What are the possible Complications of Trichorhinophalangeal Syndrome Type I?

Complications associated with Trichorhinophalangeal Syndrome Type I may include:

• Individuals with TRPS1 may have extreme pain due to arthritis, loss of bone, and limited range of motion. These may be manifested as:
  • Arthritis affecting the fingers, elbow, and spine
  • Loss of bone in the thigh
  • A prominent breastbone
  • Sideways curvature of the spine (scoliosis)
  • Backward curvature of the spine (lordosis)

  • Wing-like appearance of the shoulder blades

• Frequent respiratory infection is a recurrent complication experienced by those with the syndrome
• Degenerative hip disease is another complication associated with Trichorhinophalangeal Syndrome
• Other complications of TRPS1 may include:
  • Low blood sugar
  • Diabetes
  • Low thyroid function

How is Trichorhinophalangeal Syndrome Type I Treated?

Currently, there is no permanent cure for Trichorhinophalangeal Syndrome Type I. But, suitable measures may be adopted to relieve symptoms, correct the deformities, and manage the various complications of the syndrome.

• A correct diagnosis of the condition (at the earliest) will make it easier to prevent joint damages and avoid immobility. Consultation with a pediatric orthopedic surgeon is necessary at an early stage
• Mobility can be retained by performing orthopedic surgeries. Surgery may be required to improve the functionality of the hands
• Prosthesis may be used to replace a damaged joint such as the hip joint
• Pain medication may be used to obtain relief from pain
• Consultation with physiotherapists and occupational therapists may be beneficial in obtaining mobility, training, support, and advice on management of the syndrome
• Children with TRPS1 may be treated early by a pediatric dental specialist and may require regular monitoring, additional preventive dentistry treatment, and orthodontic treatment
• Surgery may be performed to rectify the valve between the ureter and the bladder, when recurring urinary tract infection occurs in children
• Plastic surgery may sometimes become necessary
• Children should be given psychological support during the treatment tenure

Coordination with a rehabilitation team consisting of professionals with special knowledge may be required for children with Trichorhinophalangeal Syndrome Type I. 

How can Trichorhinophalangeal Syndrome Type I be Prevented?

• Currently, there are no specific methods or guidelines to prevent Trichorhinophalangeal Syndrome Type I, since it is a genetic condition
• Genetic testing of the expecting parents (and related family members) and prenatal diagnosis (molecular testing of the fetus during pregnancy) may help in understanding the risks better during pregnancy
• If there is a family history of the condition, then genetic counseling will help assess risks, before planning for a child
• Active research is currently being performed to explore the possibilities for treatment and prevention of inherited and acquired genetic disorders

What is the Prognosis of Trichorhinophalangeal Syndrome Type I? (Outcomes/Resolutions)

• Trichorhinophalangeal Syndrome Type I does not affect the life expectancy of the individual. However, there may be complications that arise from the abnormalities such as mental retardation and asymmetry of the limbs
• Some individuals may experience severe psychological issues due to the physical abnormalities

Additional and Relevant Useful Information for Trichorhinophalangeal Syndrome Type I:

• Trichorhinophalangeal Syndrome was first described by Georg Klingmuller, a German dermatologist. It was later researched on by Leonard Langer and Andreas Giedion.
• The name of the syndrome is derived from Latin: Tricho meaning ‘hair’, rhino meaning ‘nose’, and phalanges meaning ‘finger bones’