Coffin-Siris syndrome is a rare genetic disorder that affects multiple bodily systems. Individuals with this syndrome typically have distinctive facial features and may experience developmental delays. Other symptoms may include feeding difficulties, skeletal differences, and issues with vision and hearing.

Healthcare professionals sometimes refer to Coffin-Siris syndrome as dwarfism-onychodysplasia, fifth digit syndrome, and short stature-onychodysplasia.

This article discusses Coffin-Siris syndrome, including its causes, risk factors, symptoms, diagnosis, and treatment. We also outline the prognosis for people living with Coffin-Siris syndrome.

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Doctors Coffin and Siris first described Coffin-Siris syndrome in 1970. They noted that the syndrome can affect multiple bodily systems, including:

  • the skeletal system
  • movement and dexterity
  • vision
  • hearing
  • speech

Coffin-Siris syndrome is more common in females than in males. That said, the syndrome is rare, with doctors having reported only 200 or so cases to date.

According to the National Center for Advancing Translational Services (NCATS), Coffin-Siris syndrome develops due to a mutation in one or more of the following genes:

  • ARID2
  • SMARCB1
  • SMARCE1
  • SOX11
  • DPF2

In some cases, a child may inherit Coffin-Siris syndrome from a biological parent who carries the gene mutation. In other cases, the gene mutation may occur in the child for the first time.

According to NCATS, the following are frequent symptoms of Coffin-Siris syndrome:

  • coarse facial features
  • a thick lower lip
  • a wide mouth
  • increased bodily hair
  • feeding difficulties

Other common symptoms include:

  • heart abnormalities
  • urogenital abnormalities
  • recurrent infections
  • delayed skeletal maturation and growth
  • underdevelopment of the fifth toe or finger or the fifth toenails or fingernails
  • loose joints
  • low muscle tone
  • sparse scalp hair
  • hearing difficulties
  • strabismus, when the eyes point in different directions
  • seizures
  • behavioral abnormalities

A 2021 study reports that most individuals with Coffin-Siris syndrome experience language delays. The researchers associate the condition with autism spectrum disorder and attention deficit hyperactivity disorder.

Doctors may have difficulty diagnosing Coffin-Siris syndrome. The syndrome is rare, and its symptoms can be similar to those of other conditions, such as:

  • Nicolaides-Baraitser syndrome: This is another rare syndrome, with doctors having diagnosed around 75 cases to date. Symptoms typically appear during infancy and may include:
    • delayed growth and development
    • short stature
    • sparse scalp hair
    • seizures
  • Mabry syndrome: Healthcare professionals characterize Mabry syndrome as delayed or absent speech development and delayed development of motor skills, such as sitting, crawling, and walking. Other possible symptoms include:
    • distinctive facial characteristics
    • low muscle tone
    • seizures and convulsions
  • Börjeson-Forssman-Lehmann syndrome: This is a rare syndrome that tends to occur more in males than in females. The syndrome can cause the following:
    • hormonal problems
    • seizures
    • an increased risk of diabetes

Physical differences

Doctors typically diagnose Coffin-Siris syndrome in infancy, when it is evident that the child has characteristic symptoms, such as:

  • distinctive facial features
  • underdeveloped fifth toes or toenails or fifth fingers or fingernails
  • decreased muscle tone

An older study from 1991 explains that facial differences may not help doctors determine if a person has Coffin-Siris syndrome, as these symptoms also appear in individuals with other rare disorders.

However, other features, such as the underdevelopment of an organ, can help healthcare professionals diagnose Coffin-Siris syndrome.

Molecular testing

A 2022 study mentions that doctors can diagnose Coffin-Siris syndrome via molecular testing while the fetus is in the womb. This involves taking samples of the fetal cells through the placenta between weeks 10 and 12 of pregnancy.

An ultrasound scan can also help doctors check for abnormalities of the heart or kidneys in the developing fetus.

Imaging tests

Imaging tests can help doctors check for signs associated with Coffin-Siris syndrome.

An MRI scan can help doctors assess any soft tissue abnormalities, while X-rays can help doctors assess bone development.

The treatment for Coffin-Siris syndrome depends on the symptoms a person develops.

Treatment options may include:

  • Wearing glasses: The American Academy of Ophthalmology states that glasses can help correct strabismus. Some individuals may benefit from prism glasses that help correct double vision.
  • Undergoing eye surgery: Ophthalmologists may recommend eye surgery to correct strabismus. Surgery involves weakening or loosening the eye muscles and repositioning the eyes so that they are looking in the same direction.
  • Attending speech therapy sessions: Speech therapy may be beneficial for individuals with delayed or absent speech. A speech therapist can help strengthen a person’s speech muscles and improve pronunciation.
  • Undergoing a gastrostomy tube placement procedure: According to the United Kingdom’s National Health Service (NHS), a feeding tube may be necessary for people who cannot swallow food.

There are no long-term studies outlining the life expectancy of people with Coffin-Siris syndrome.

The NCATS states that individuals living with rare diseases may face challenges, including:

  • receiving limited information about their condition and its treatment
  • facing financial difficulties due to medical costs
  • feeling socially isolated or withdrawn

People with Coffin-Siris syndrome or other rare conditions may benefit from joining a rare disease organization (RDO). These can provide access to additional information and resources relating to a person’s condition. They can also help people gain access to financial support and counseling. A person can speak with a doctor about joining an RDO.

Coffin-Siris syndrome is a rare condition that typically involves distinctive facial characteristics and developmental delays. Other symptoms can vary from person to person, depending on the type of gene mutation.

Doctors typically diagnose Coffin-Siris syndrome in infancy, using a combination of physical examinations and imaging tests. Alternatively, doctors can use molecular testing to diagnose the condition in utero.

The treatment for Coffin-Siris syndrome depends on the symptoms a person experiences. People can consult a doctor about their options for treatment. They may also wish to consider joining an RDO for practical, financial, and emotional support.