Which are the causes of Aarskog-Scott Syndrome?

Aarskog-Scott Syndrome, also known as faciogenital dysplasia, is a rare genetic disorder that primarily affects males. It is characterized by a variety of physical, developmental, and skeletal abnormalities. The syndrome was first described by Dagfinn Aarskog, a Norwegian pediatrician, in 1970.

The exact cause of Aarskog-Scott Syndrome is a mutation in the FGD1 gene, which is located on the X chromosome. This gene provides instructions for producing a protein that is involved in the development and maintenance of various tissues in the body. The mutation in the FGD1 gene leads to a deficiency or dysfunction of the protein, resulting in the characteristic features of the syndrome.

Aarskog-Scott Syndrome is inherited in an X-linked recessive manner. This means that the gene mutation is located on the X chromosome, one of the two sex chromosomes. Males have one X and one Y chromosome, while females have two X chromosomes. Since the FGD1 gene is located on the X chromosome, males are more commonly affected by the syndrome than females.

Carrier females, who have one copy of the mutated gene and one normal gene, are usually unaffected or may exhibit mild symptoms. However, they have a 50% chance of passing the mutated gene to their children. If a carrier female has a son, there is a 50% chance that he will inherit the syndrome. If a carrier female has a daughter, there is a 50% chance that she will also be a carrier.

The specific symptoms of Aarskog-Scott Syndrome can vary widely among affected individuals. However, some common features include:

• Facial abnormalities: These may include a broad forehead, widely spaced eyes (hypertelorism), a flat nasal bridge, a short upturned nose, and a widow's peak hairline.


• Genital abnormalities: Males with the syndrome may have an unusually small penis (micropenis) and undescended testicles (cryptorchidism).


• Short stature: Individuals with Aarskog-Scott Syndrome are often shorter than average.


• Hand and finger abnormalities: These may include short fingers, a single crease in the palm (simian crease), and webbing or fusion of the skin between the fingers (syndactyly).


• Developmental delays: Some individuals may experience delays in reaching developmental milestones, such as walking and talking.

Other less common features of the syndrome may include heart defects, abnormalities of the skeletal system (such as scoliosis or extra fingers or toes), intellectual disability, and behavioral issues.

Diagnosis of Aarskog-Scott Syndrome is typically based on the presence of characteristic physical features and a thorough medical evaluation. Genetic testing can confirm the diagnosis by identifying the specific mutation in the FGD1 gene.

Treatment for Aarskog-Scott Syndrome is focused on managing the individual symptoms and may involve a multidisciplinary approach. This may include surgical interventions for correcting certain abnormalities, physical therapy to improve motor skills, speech therapy for language delays, and educational support for learning difficulties.

In conclusion, Aarskog-Scott Syndrome is a rare genetic disorder caused by a mutation in the FGD1 gene on the X chromosome. It is inherited in an X-linked recessive manner and primarily affects males. The syndrome is characterized by a range of physical, developmental, and skeletal abnormalities. Early diagnosis and appropriate management can help improve the quality of life for individuals with Aarskog-Scott Syndrome.