Trichorhinophalangeal syndrome type III

Trichorhinophalangeal syndrome type III (TRPS III), also known as Sugio-Kajii syndrome, is a rare genetic disorder characterized by distinctive facial features, abnormalities in the growth and development of hair, bones, and teeth, and other physical anomalies. This condition is part of a group of related disorders known as the trichorhinophalangeal syndromes, which also includes Trichorhinophalangeal syndrome type I and Trichorhinophalangeal syndrome type II (also known as Langer-Giedion syndrome). TRPS III is the least common of the three types.

Symptoms and Characteristics

The hallmark features of TRPS III include sparse scalp hair, a bulbous tip of the nose, a long flat philtrum, and a thin upper lip. Individuals with this condition often have unique skeletal abnormalities such as cone-shaped epiphyses in the hands and feet, short stature, and variable degrees of intellectual disability. Unlike TRPS I and II, TRPS III does not typically involve multiple exostoses (abnormal bony growths).

Genetics

TRPS III is caused by mutations in the TRPS1 gene, which plays a crucial role in the development and growth of various tissues, including bone and hair. The condition is inherited in an autosomal dominant pattern, meaning that only one copy of the altered gene in each cell is sufficient to cause the disorder. However, there are cases where the mutation occurs for the first time in an individual with no family history of the condition, known as a de novo mutation.

Diagnosis

Diagnosis of TRPS III is based on a combination of clinical evaluation, detailed patient history, and genetic testing to identify mutations in the TRPS1 gene. Radiographic imaging may also be used to observe characteristic skeletal abnormalities associated with the syndrome.

Management and Treatment

There is no cure for TRPS III, and treatment is symptomatic and supportive. Management may include physical therapy to improve mobility and prevent joint stiffness, dental care to address dental anomalies, and counseling to support intellectual and emotional development. In some cases, growth hormone therapy may be considered to address short stature.

Prognosis

The prognosis for individuals with TRPS III varies depending on the severity of symptoms and the effectiveness of management strategies. With appropriate care, most individuals can lead active, fulfilling lives.