Definition of Pfeiffer syndrome

Pfeiffer syndrome: A syndrome of craniosynostosis (premature fusion of the cranial sutures) due to mutation in FGFR (fibroblast growth factor receptor) characterized by bulging eyes (proptosis) due to shallow eye sockets, underdevelopment of the midface and broad short thumbs and big toes.

There are three types of Pfeiffer syndrome:

• Pfeiffer syndrome type 1 -- The intellect is usually normal. There is moderate to severe underdevelopment (hypoplasia) of the midface, broad and inwardly deviated thumbs and big toes with variable degree of shortening of the digits (brachydactyly). Hydrocephalus and hearing loss may also occur.

• Pfeiffer syndrome type 2 -- Developmental delay and mental retardation are common. There is a cloverleaf skull and extreme proptosis. The thumbs, big toes and other digits are as in type 1 but there is also ankylosis (fusion) of the elbows and knees. Other problems may include narrowing or closure of the nasal passages, laryngeal and tracheal malformations, hydrocephalus and seizures.

• Pfeiffer syndrome type 3 -- There is a tall short skull (turribrachycephaly). All other features are as in type 2.

Pfeiffer syndrome is inherited in an autosomal dominant manner. Type 1 is due to mutation in the FGFR1 and (more often) FGFR2 genes. Types 2 and 3 are due to mutation in the FGFR1 gene.

The health care of children with Pfeiffer syndrome is often best managed by a multidisciplinary team which may include a neurosurgeon, plastic surgeon, otolaryngologist, dentist, audiologist, speech pathologist, pediatrician, and geneticist. A dozen or more surgeries may be required over a lifetime. The first surgery is usually to relieve the premature fusion of the cranial sutures. Hydrocephalus, upper airway obstruction, and exposure of the cornea by the proptosis may require shunting, tracheostomy, and surgical eyelid closure, respectively.

The prognosis (outlook) is most favorable with Pfeiffer syndrome type 1. Types 2 and 3 carry an increased risk of early death.