Pfeiffer syndrome is a genetic disorder that results from mutations in FGFR1 and FGFR2 genes, with the abnormal gene inherited from either parent or the result of a new mutation.
Pfeiffer syndrome is a genetic disorder characterized by the premature fusion of skull bones and abnormally broad and medially deviated thumbs and great toes. This early fusion prevents the skull from growing normally and affects the shape of the head and face. Moreover, it can also affect bones in the hands and feet. Studies show that 1 out of every 100,000 people have this condition.
Causes of Pfeiffer syndrome:
Pfeiffer syndrome is an autosomal dominant genetic disorder, which means even one copy of the defective gene (from either parent) can result in the disease. The syndrome is associated with mutations in FGFR1 and FGFR2 genes, and the abnormal gene can be inherited from either parent or can be the result of a new mutation.
Advanced paternal age is associated with an increased risk of new mutations for Pfeiffer syndrome. The risk of passing the abnormal gene from an affected parent to offspring is 50 percent for each pregnancy and is equal for both men and women.
Subtypes of Pfeiffer syndrome
Pfeiffer syndrome can be broken down into the following three subtypes, each with an increase in severity.
Type I
- Characterized by premature fusion of the skull, finger and toe abnormalities and sunken cheekbones.
- The neurological development and intellectual ability of a child are usually on par with those of other children.
- Patients may have a fluid buildup in their brain and hearing loss.
- Since this is a milder form of the syndrome, individuals usually have a normal life span, provided the condition is successfully treated.
Type II
- Patients have cloverleaf-shaped skulls, resulting from the excessive fusion of the skull bones, as well as:
- Abnormal eye protrusions, which may affect vision
- Fused elbow joints
- Fused knee joints
- Finger abnormalities
- Toe abnormalities
- Developmental delays
- Neurological complications
- Type II of the syndrome causes severe neurological deficits, has a poor prognosis and often results in early death.
Type III
- Type III causes the same disabilities as type II, except for the cloverleaf-shaped skull.
- Outlook for people with type III of the syndrome is also often poor and may result in early death.
What are the signs and symptoms of Pfeiffer syndrome?
Depending on the type and severity, signs and symptoms of Pfeiffer syndrome could include:
- Bulging eyes
- Wide-set eyes
- High forehead
- Beaked nose
- Underdevelopment of the upper jaw
- Prominent lower jaw
- Protrusion of the eyes
- Hearing loss (in more than 50 percent of those affected)
- Short fingers and toes
- Webbing or fusion between the digits
- Dental problems
- Wide thumbs and big toes that bend away from the other digits
- Cloverleaf-shaped head (in type II Pfeiffer syndrome)
How is Pfeiffer syndrome diagnosed?
Pfeiffer syndrome is diagnosed through imaging studies and a physical exam to confirm the presence of:
- Premature bone fusions in the skull
- Fused elbow and knee joints
- Finger and toe abnormalities
Other genetic conditions may need to be ruled out, and molecular genetic testing will usually be conducted to confirm gene mutations.
How is Pfeiffer syndrome treated?
Children with Pfeiffer syndrome often endure multiple complex surgeries to repair skull and joint deformities. Surgery to release the prematurely fused skull is undertaken within the child’s first year of life to promote normal brain and skull growth.
Surgeons can repair the child’s eye sockets at the same time to preserve their vision. Other face structure surgery, including the cheekbones and jaws, and surgery on the child’s webbed hands and feet are performed when the child is older.
Some children will need the following treatments to manage their breathing problems:
- Surgery to release blockages of the midface
- Surgery to remove the tonsils or adenoids
- Continuous positive airway pressure (CPAP) therapy involving the use of a special mask while sleeping
- Tracheostomy (severe cases)