What Causes Aarskog Scott Syndrome?

Medically Reviewed on 10/21/2021
Aarskog Scott syndrome
Aarskog syndrome is a genetic disorder caused by mutations in a gene called FGD1.

Aarskog Scott syndrome (also called Aarskog syndrome, Aarskog disease, faciodigitogenital syndrome, or faciogenital dysplasia) is a rare genetic disease.

  • The exact cause of Aarskog Scott syndrome is not known in most cases.
  • In about 20 percent of the cases, however, the cause of Aarskog Scott syndrome is the mutation in the FDG1 gene.

This gene contains the information needed to activate a protein called Cdc42, which further transmits signals necessary for proper development before and after birth. It is particularly essential for the optimal development of bones.

The FGD1 gene may play a role in extracellular matrix maintenance or remodeling. The extracellular matrix is a complex arrangement of proteins and other molecules in the intercellular spaces (the spaces between cells). The FDG1 plays a crucial role in the development of blood vessels, as well.

What are the symptoms of Aarskog Scott syndrome?

Aarskog Scott syndrome is mainly characterized by short stature along with several abnormalities in the structure of the limbs, face, and genitals. The condition primarily affects males and may exhibit varying degrees of severity among the affected people.

The major signs and symptoms of Aarskog Scott syndrome include:

  • Short stature
  • Broad forehead
  • Round face
  • Short neck with or without webbing
  • Widow’s peak hairline
  • Widely spaced eyes (hypertelorism)
  • Crossed eyes (strabismus)
  • Restricted eye movements
  • Droopy eyelids
  • Short nose
  • Cleft lip or palate (incomplete closure of the roof of the mouth or a vertical groove in the upper lip)
  • Broad nasal bridge
  • Upturned nose, allowing the nostrils to be visible from the front (anteverted nostrils)
  • Long philtrum (the fold of skin between the upper part of the lip and nose)
  • Delayed teeth eruption
  • Ear abnormalities, such as a slightly folded top portion of the ear
  • Vision abnormalities
  • Dental abnormalities, such as missing teeth and defective enamel
  • Broad and short hands
  • Mildly sunken chest
  • Short fingers and toes (brachydactyly)
  • Fixation of the fifth fingers in a bent position (clinodactyly)
  • Webs of the skin between fingers and toes (interdigital webbing)
  • Broad and flat feet with thick toes
  • Undescended testes (cryptorchidism)
  • Shawl scrotum (the scrotum appears to surround the penis like a shawl)
  • Inguinal hernia (seen as a bulge in the groin region)
  • The scrotum may appear to be divided or have a cleft (bifid scrotum)
  • The opening of the urinary meatus present on the under-surface of the penis (hypospadias)
  • Mild learning difficulties
  • Failure to thrive (inability to gain weight and height at an expected rate)
  • Abnormal side to side curvature of the spine (scoliosis)

Further examination and investigations may reveal additional or supernumerary ribs, heart defects, abnormal blood vessels in the eyes, and decreased bone age. Diagnosis should be confirmed through genetic testing.

How is Aarskog Scott syndrome treated?

Presently, there is no cure for Aarskog Scott syndrome. The treatment mainly involves managing the symptoms and preventing any complications. Because the disease affects the physical features as well, psychiatric counseling may also be needed.

Generally, a team approach is needed for treatment, consisting of various specialists, such as pediatricians, eye surgeons, cardiologists, general surgeons, dentists, vascular surgeons, and speech therapists.

Medically Reviewed on 10/21/2021
Medline Plus. Aarskog-Scott Syndrome. https://medlineplus.gov/genetics/condition/aarskog-scott-syndrome/#inheritance

Orrico A. Aarskog Syndrome. National Organization for Rare Disorders. https://rarediseases.org/rare-diseases/aarskog-syndrome/