Trichorhinophalangeal syndrome type I

Trichorhinophalangeal syndrome type I
Synonyms	TRPS I
Pronounce	N/A
Specialty	N/A
Symptoms	Sparse hair, bulbous nose, short stature, brachydactyly
Complications	N/A
Onset	Congenital
Duration	Lifelong
Types	N/A
Causes	Genetic mutation in the TRPS1 gene
Risks	Family history
Diagnosis	Clinical evaluation, genetic testing
Differential diagnosis	N/A
Prevention	N/A
Treatment	Symptomatic management
Medication	N/A
Prognosis	Variable
Frequency	Rare
Deaths	N/A

Trichorhinophalangeal syndrome type I (TRPS I) is a rare genetic disorder characterized by distinctive craniofacial and skeletal abnormalities. It is one of the three types of trichorhinophalangeal syndromes, which are distinguished by their clinical features and genetic causes.

Etiology

TRPS I is caused by mutations in the TRPS1 gene, which is located on chromosome 8q24.12. The TRPS1 gene encodes a transcription factor that is involved in the regulation of chondrocyte proliferation and differentiation, which are critical processes in the development of bones and cartilage.

Clinical Features

Individuals with TRPS I typically present with a combination of craniofacial dysmorphism, skeletal abnormalities, and ectodermal features.

Craniofacial Features

• Sparse scalp hair: Patients often have thin, slow-growing hair.
• Bulbous nose: A rounded nasal tip is a characteristic feature.
• Long philtrum: The groove between the nose and the upper lip is elongated.
• Thin upper lip: The upper lip may appear thin and flat.

Skeletal Abnormalities

• Brachydactyly: Shortening of the fingers and toes due to abnormal bone development.
• Cone-shaped epiphyses: The ends of the long bones in the fingers may be cone-shaped, visible on X-rays.
• Short stature: Affected individuals may have below-average height.

Ectodermal Features

• Sparse body hair: In addition to scalp hair, body hair may also be sparse.
• Nail abnormalities: Nails may be thin and brittle.

Diagnosis

Diagnosis of TRPS I is based on clinical evaluation and confirmed by genetic testing. The presence of characteristic physical features, along with radiographic findings of cone-shaped epiphyses, can suggest the diagnosis. Genetic testing can identify mutations in the TRPS1 gene, confirming the diagnosis.

Management

There is no cure for TRPS I, and treatment is primarily supportive and symptomatic. Management strategies may include:

• Orthopedic interventions for skeletal abnormalities.
• Dermatological care for skin and hair issues.
• Genetic counseling for affected individuals and their families.

Prognosis

The prognosis for individuals with TRPS I varies depending on the severity of symptoms. While the condition is lifelong, many individuals can lead relatively normal lives with appropriate management of symptoms.

Epidemiology

TRPS I is a rare disorder, with an estimated prevalence of less than 1 in 1,000,000. It affects both males and females equally and has been reported in various ethnic groups.

See Also

• Trichorhinophalangeal syndrome type II
• Trichorhinophalangeal syndrome type III
• Genetic disorders

External Links

• Genetic and Rare Diseases Information Center