Tricho-Rhino-Phalangeal Syndrome Type 2

What Is Tricho-Rhino-Phalangeal Syndrome Type 2?

Tricho-rhino-phalangeal syndrome (TRPS 2) is a rare disorder affecting multiple systems in the body. TRPS 2 is an inherited condition, which means it is genetically passed down from parents to their children. TRPS 2 is also known as Langer Giedion syndrome. The name of the condition describes some of the frequently affected areas in the body; tricho (hair), rhino (nose), and phalanges (fingers and toes). TRPS 2 is a disorder that results in abnormalities of the skin, hair, teeth, sweat glands, and nails, in addition to bone and joint malformations, unusual facial traits, and intellectual incapacity. Symptoms fluctuate widely in type and severity in different cases. The absence of genetic material in chromosome 8 is the primary cause of TRPS 2. Tricho-rhino-phalangeal syndrome type 2 can also cause the development of several osteochondromas in the affected individual. These osteochondromas are benign tumors of the bone.

What Are the Other Names of Tricho-Rhino-Phalangeal Syndrome Type 2?

Other names of the condition are:

• TRPS 2.

• TRPS II.

• Langer Giedion syndrome.

• LGS.

• Tricho-rhino-phalangeal syndrome with exostoses.

• Chromosome 8q 24.1 deletion syndrome.

What Causes Tricho-Rhino-Phalangeal Syndrome Type 2?

The causes of tricho-rhino-phalangeal syndrome type 2 include the following:

• The majority of the cases develop as a result of chromosome deletion (absence of genetic matter). This deletion of chromosomes is inherited from parents to their children in an autosomal dominant manner, which means only one copy of the mutated gene is sufficient to cause the condition. Although people with TRPS 2 rarely have children.

• TRPS 2 occurs due to mutation or function loss of various adjacent genes. This is known as contagious gene syndrome. These genes are located on the long arm of chromosome number 8. Scientists have identified two genes that can cause TRPS 2. These genes are; TRPS 1 gene and the EXT1 (exostosin-1) gene. Additionally, the RAD21 gene can also cause many symptoms associated with TRPS 2.

• Multiple osteochondromas reported in TRPS 2 patients have been linked to the deletion of the EXT1 gene. The other deformities of the bones and the face are thought to be caused by TRPS 1 gene loss as well.

• Intellectual disability may be exacerbated by RAD21 gene deletion. The extra characteristics of this condition are probably caused by the deletion of other genes from this section of chromosome 8.

What Are the Symptoms of Tricho-Rhino-Phalangeal Syndrome Type 2?

The symptoms of tricho-rhino-phalangeal syndrome type 2 are:

• Thin and fine hair.

• Atypical facial features.

• Short height or stature may be seen in the affected individual.

• Multiple bone growth projects from several bones of the body (exostoses).

• Abnormalities of the skin.

• Loss of muscle tone (hypotonia).

• Mental impairment or mental retardation.

• At birth, affected babies may have hair that is noticeably thin and sparse. This hair is excessively brittle and slow-growing.

• Most patients lose most of the hair present on their scalp by the second decade of their life.

• Affected individuals have multiple osteochondromas (benign bone tumors). Osteochondromas can result in pain, restricted joint motion, and injury to blood vessels or the spinal cord, depending on their location.

• Reduced bone density (osteopenia).

• Slow or delayed growth that results in short height or stature.

• Babies with TRPS 2 have abnormalities associated with their head and face, such as microcephaly (a disorder in which the head circumference is smaller than normal for the infant's age and gender).

• Large, rounded, bulbous nose with thick nostrils and broad nasal bridge.

• Large ears that appear protruding.

• The jaw is abnormally small in size.

• Jaws are placed posteriorly (retrognathia).

• Philtrum (the groove in the upper lip area) is long and deep.

• Widely spaced eyes and deviation of one eye from the other.

• Dental problems like the presence of supernumerary teeth or the absence of some teeth.

• Thin, narrow ribs, unusual shoulder blades that resemble wings, webbing of some fingers and toes, and scoliosis are additional skeletal abnormalities that may be present.

• Mental retardation is seen at birth in many infants which ranges from mild to severe. In other instances, mental retardation could not be apparent until late infancy or early childhood. However, intelligence level may be average in about 25 percent of the affected population.

What Is the Prevalence of Tricho-Rhino-Phalangeal Syndrome Type 2?

• The trichi-rhino-phalangeal syndrome is very rare, and the exact incidence rate of the condition is unknown because of less number of reported cases.

• However, the condition is known to affect men three times more as compared to women.

• Approximately 60 cases of this condition have been reported to date.

What Is the Diagnosis of Tricho-Rhino-Phalangeal Syndrome Type 2?

• The diagnosis of tricho-rhino-phalangeal syndrome can be tricky because there are several conditions with similar signs and symptoms. However, tricho-rhino-phalangeal syndrome type 2 may occasionally be suspected at birth by a thorough clinical assessment and the identification of distinguishing features. Unusual facial features, such as a wide, bulbous nose, thin, sparse hair, or extra skin, are examples of abnormalities that are typically evident at birth. These symptoms can easily help diagnose the condition at a very early age.

• Molecular testing is the definitive diagnostic procedure that can help confirm TRPS 2 by identifying changes in the TRPS 1 gene and the EXT1 gene.

• Imaging tests like an X-ray or CT (computed tomography) scan may help determine the bone abnormalities associated with TRPS 2. In these imaging tests, several characteristic features like multiple bony growths, low bone density, osteochondromas, and epiphyseal coning of the bone can be easily seen.

• Early infants may not show signs of mental retardation, hearing loss, or speech problems. These signs of mental retardation can only be identified in early childhood.

What Is the Treatment of Tricho-Rhino-Phalangeal Syndrome Type 2?

• The treatment of tricho-rhino-phalangeal syndrome type 2 is generally specific for each individual (depending upon the presenting symptom), and the treatment usually involves symptomatic relief. The treatment is usually multidisciplinary and involves the combined efforts of several medical specialists.

• In some cases, treatment may involve surgically removing several exostoses that cause pain, and nerve compression, preventing appropriate limb development, and limiting some movements.

• An affected person's capacity to do specific movements more easily may also be improved by physical therapy when used in conjunction with other supportive interventions.

• Significant hearing loss may be treated with hearing aids.

• Regular follow-up and monitoring are necessary to prevent recurrent respiratory tract infections.

• In order to ensure that children with TRPS 2 attain their full potential, early intervention is crucial. Speech therapy, among other medical, social, and occupational treatments, are unique services that may be advantageous to affected children.

Conclusion

Trchi-rhino-phalangeal syndrome type 2 or TRPS 2 is an extremely rare medical condition that affects multiple systems of the body. The condition primarily affects the hair, nose, facial features, fingers, bones, and mental abilities. The diagnosis and treatment vastly depend on each individual’s presenting symptoms. An early diagnosis and intervention may help the affected child in reaching their full abilities. With early diagnosis and effective treatment, the condition can have a better prognosis.