Coffin-Siris Syndrome

What is Coffin-Siris syndrome?

Coffin-Siris syndrome is a rare genetic disorder that may be evident at birth. It is characterized by abnormalities of the head and craniofacial area that results in a coarse facial appearance. In addition, affected children usually have malformations in the fingers and toes, and eye abnormalities.

What causes Coffin-Siris syndrome?

Mutations in the following five different genes have all been found to cause Coffin-Siris syndrome: ARID1A, ARID1B, SMARCA4, SMARCB1, and SMARCE1. Researchers speculate that these mutations are transmitted through autosomal dominant inheritance, but most cases appear to be as the result of a new mutation.

What are the symptoms of Coffin-Siris syndrome?

The specific signs and symptoms and their severity varies among the affected patients. Most prominently, individuals with Coffin-Siris syndrome will have coarse facial features, which include the following:

• Unusually small head
• Wide mouth with full, distinctive lips
• Broad nasal tip
• Low nasal bridge
• Abnormally long vertical groove between the nose and upper lip
• Excessive hair growth, with thick eyebrows and long eyelashes, but sparse scalp hair

Characteristic skeletal abnormalities are also common in Coffin-Siris syndrome. These include:

• Unusually short digits
• Underdeveloped or absent fingernails and toenails
• Dislocation of the inner forearm bone at the elbow
• Deformity of the hip
• Unusually small or absent knee caps

Overall, these abnormalities are all coupled with feeding difficulties, vomiting, slow growth, failure to thrive, frequent respiratory infections, and delayed motor skills and speech ability.

How is Coffin-Siris syndrome diagnosed?

Coffin-Siris syndrome is suspected in newborns that have the characteristic features of the disease, specifically, underdeveloped nails and short fingers and toes. The abnormal facial features of the disease become more apparent as the child grows. Diagnosis is ultimately made after a thorough clinical evaluation and certain specialized testing to establish the extent of the disorder. Molecular genetic testing is also helpful to confirm a diagnosis.

What are the available treatments for Coffin-Siris syndrome?

Unfortunately, there is no cure for Coffin-Siris syndrome, so treatment is symptomatic and supportive at this time. Surgical repair of the craniofacial and skeletal features of the disease may be conducted, depending on the severity of the abnormalities. In addition, special education and physical, speech, and occupational therapy can also help with some of the complications of Coffin-Siris syndrome.

Where can I find more information on Coffin-Siris syndrome?

• National Organization for Rare Disorders (NORD)
• NIH
• U.S. National Library of Medicine