Aarskog–Scott syndrome

A genetic disorder affecting physical development

Aarskog–Scott syndrome is a rare genetic disorder that affects a person's physical development. It is primarily characterized by distinctive facial features, short stature, and abnormalities of the hands, feet, and genitalia. The syndrome is named after Dagfinn Aarskog, a Norwegian pediatrician, and Charles I. Scott, Jr., an American medical geneticist, who independently described the condition.

Genetics

X-linked recessive inheritance pattern

Aarskog–Scott syndrome is inherited in an X-linked recessive pattern. This means that the gene responsible for the syndrome is located on the X chromosome. Males, who have only one X chromosome, are more severely affected by the disorder. Females, with two X chromosomes, may be carriers and can exhibit mild symptoms due to the presence of one normal copy of the gene.

The gene associated with Aarskog–Scott syndrome is the FGD1 gene, which provides instructions for making a protein involved in the regulation of the actin cytoskeleton, a structure that helps cells maintain their shape and internal organization.

Clinical Features

Individuals with Aarskog–Scott syndrome often present with a range of clinical features:

Facial Features

- Hypertelorism: Widely spaced eyes. - Downslanting palpebral fissures: The outer corners of the eyes are lower than the inner corners. - Ptosis: Drooping of the upper eyelids. - Broad nasal bridge: The area between the eyes is wider than usual. - Philtrum: A pronounced groove between the nose and upper lip.

Skeletal Abnormalities

- Short stature: Individuals are often shorter than average for their age. - Brachydactyly: Short fingers and toes. - Clinodactyly: Curved fingers, often the fifth finger.

Genital Abnormalities

- Shawl scrotum: A condition where the scrotum surrounds the penis like a shawl. - Cryptorchidism: Undescended testicles.

Other Features

- Mild intellectual disability: Some individuals may have learning difficulties. - Delayed motor development: Such as late walking.

Diagnosis

Diagnosis of Aarskog–Scott syndrome is based on clinical evaluation and the identification of characteristic physical features. Genetic testing can confirm the diagnosis by identifying mutations in the FGD1 gene.

Management

There is no cure for Aarskog–Scott syndrome, and treatment is symptomatic and supportive. Management may include: - Growth hormone therapy: To address short stature. - Surgical intervention: For cryptorchidism or other anatomical abnormalities. - Educational support: For learning difficulties.

Prognosis

The prognosis for individuals with Aarskog–Scott syndrome is generally good, with most individuals leading a normal lifespan. However, the degree of physical and intellectual disability can vary widely among affected individuals.

Related pages

• Genetic disorder
• X-linked recessive inheritance
• Skeletal dysplasia