Schinzel-Giedion Syndrome (SGS)

What is Schinzel-Giedion syndrome (SGS)?

Schinzel-Giedion (SGS) syndrome is a very rare, severe genetic disorder that appears at birth and affects many body systems. Its characteristic symptoms feature distinctive facial features, neurological problems, and organ and bone abnormalities. While the exact prevalence of it is unknown, SGS is very rare.

What are the symptoms of Schinzel-Giedion syndrome?

Symptoms for SGS may include:

• Distinctive facial features:
  • Middle of the face looking like it has been drawn inward
  • Large or bulging forehead
  • Wideset eyes
  • Short, upturned nose
  • Wide mouth with a large tongue
  • Short and wide neck
  • Ear malformations
  • Inability to secrete tears
  • Excessive hairiness
• Neurological problems:
  • Severe developmental delay/intellectual disability
  • Feeding problems
  • Sleep apnea
  • Seizures
  • Visual or hearing problems
  • Recurring infections
• Organ abnormalities:
  • Obstruction of the tube that carries urine from the kidney to the bladder, which causes accumulation of urine in the kidneys
  • Heart defects: problems with the heart valves, ventricles, and/or the septum
  • Underdevelopment of the genitals
• Bone abnormalities:
  • Abnormally hard or thick bones at base of skull
  • Large gaps between the bones of the skull
  • Broad ribs
  • Abnormal collarbones
  • Short lower legs and arms
  • Shortened bones at the ends of fingers
• Children who survive past infancy may develop certain kinds of tumors called neuroepithelial tumors

What causes Schinzel-Giedion syndrome?

SGS is caused by new mutations in the SETBP1 gene that are not inherited from a patient’s parents. The mutations that have been identified in SGS cluster in a region of the gene called exon 4. However, the effects of the mutations on the function of the gene and the proteins it makes are unknown; researchers are currently working to find out how the mutation causes the symptoms of SGS.

How is Schinzel-Giedion syndrome diagnosed?

Schinzel-Giedion syndrome is diagnosed using the following procedures:

• Clinical findings of characteristic symptoms
• Presence of hydronephrosis (accumulation of urine in the kidneys) on an ultrasound
• X-ray findings of skeletal malformation
• Genetic testing to find mutations in the SETBP1 gene

What are the treatments for Schinzel-Giedion syndrome?

Since this disease is quite severe, most treatment is focused on symptoms and relieving pain. This may include:

• Surgery to drain excess urine from the kidneys
• Surgery to treat septal defects in the heart
• Anti-convulsant drugs to help prevent and control seizures
• Genetic counseling

Where can I find out more about Schinzel-Giedion syndrome?

• National Organization for Rare Disorders (NORD)
• NIH