Pfeiffer syndrome is a genetic disorder characterized by the premature fusion of certain skull bones (craniosynostosis). This early fusion prevents the skull from growing normally and affects the shape of the head and face. Pfeiffer syndrome also affects bones in the hands and feet.
Many of the characteristic facial features of Pfeiffer syndrome result from premature fusion of the skull bones. Abnormal growth of these bones leads to bulging and wide-set eyes, a high forehead, an underdeveloped upper jaw, and a beaked nose. More than half of all children with Pfeiffer syndrome have hearing loss; dental problems are also common.
In people with Pfeiffer syndrome, the thumbs and first (big) toes are wide and bend away from the other digits. Unusually short fingers and toes (brachydactyly) are also common, and there may be some webbing or fusion between the digits (syndactyly).
Pfeiffer syndrome is divided into three subtypes. Type 1, also known as classic Pfeiffer syndrome, has symptoms as described above. Most individuals with type 1 Pfeiffer syndrome have normal intelligence and a normal life span. Types 2 and 3 are more severe forms of Pfeiffer syndrome that often involve problems with the nervous system. The premature fusion of skull bones can limit brain growth, leading to delayed development and other neurological problems. Type 2 is distinguished from type 3 by the presence of a cloverleaf-shaped head, which is caused by more extensive fusion of bones in the skull.
what causes pfeiffer syndrome?
There is no link between what the mother did or did not do during the pregnancy. Instead, Pfeiffer syndrome is caused by a mutation (change) in the gene for the ﬁbroblast growth factor receptor (FGFR 1 or 2). The FGFR genes play an important role in signaling a cell to divide or mature. A malfunction of this gene may therefore cause premature fusion of the bones of the skull, ﬁngers or toes. Some studies show that Pfeiffer syndrome occurs more often in children with older fathers.
what types of pfeiffer syndrome are there?
pfeiffersyndrome has been divided into three subtypes based on the severity ofsymptoms:
Type 1 – Individuals with type 1 Pfeiffersyndrome have premature fusion of the cranialsutures, recessed cheekbones, and ﬁnger and toe abnormalities. Neurologic development and intellect are usually normal. Hydrocephalus(build up of ﬂuid around the brain) and hearing losscan occur.
Type 2 – Individuals with type 2 Pfeiffersyndrome have a “cloverleaf” shaped skull deformity because of extensive fusion of the cranialsutures. Proptosis(abnormal protrusion) of the eyes, ﬁnger and toe abnormalities, and fusion of the elbow and knee joints(ankylosis) are also common. The cloverleafskullcan cause limited brain growth and mental retardation. The proptosis of the eyescan cause severe visual problems. Many of these individuals have developmental delay and mental retardation.
Type 3 – These individuals have similar featuresto type 2 Pfeiffer Syndrome, however they do not have the cloverleaf skull.
How is pfeiffer syndrome diagnosed?
The diagnosis of Pfeiffer Syndrome is made on the presence of premature fusion of the cranial bones and broad,short thumbs and ﬁrst toes. Othersyndromes considered when making the diagnosisinclude Apert, Crouzon, Saethre-Chotzen and Jackson-Weiss.It is difﬁcult to make the diagnosis on a prenatal ultrasound, because the clinical features of Pfeiffersyndrome