Pfeiffer syndrome
Encyclopedia
Pfeiffer syndrome is a rare genetic disorder
Genetic disorder
A genetic disorder is an illness caused by abnormalities in genes or chromosomes, especially a condition that is present from before birth. Most genetic disorders are quite rare and affect one person in every several thousands or millions....

 characterized by the premature fusion of certain bones of the skull (craniosynostosis
Craniosynostosis
Craniosynostosis is a condition in which one or more of the fibrous sutures in an infant skull prematurely fuses by ossification, thereby changing the growth pattern of the skull...

), which prevents further growth of the skull
Human skull
The human skull is a bony structure, skeleton, that is in the human head and which supports the structures of the face and forms a cavity for the brain.In humans, the adult skull is normally made up of 22 bones...

 and affects the shape of the head and face. It is named after Rudolf Arthur Pfeiffer (1931-) who, in 1964, described a list of features that included a coronal synostosis, turribachycephaly (high prominent forehead) and maxillary hypoplasia (eyes with a bulging appearance due to small underlying cheek bones). Pfeiffer syndrome affects about 1 in 100,000 births.

Genetics

Pfeiffer syndrome is strongly associated with mutations of Fibroblast growth factor receptor 1 and 2. These receptors are important for normal bone development.

Presentation

Many of the characteristic facial features that Pfeiffer described in Pfeiffer syndrome result from the premature fusion of the skull bones. The head is unable to grow normally, which leads to eyes that appear to bulge (proptosis) and are wide-set (hypertelorism), an underdeveloped upper jaw, and a beaked nose. About 50 percent of children with Pfeiffer syndrome have hearing loss (see hearing loss with craniofacial syndromes
Hearing loss with craniofacial syndromes
Hearing loss with craniofacial syndromes is a common occurrence. Many of these multianomaly disorders involve structural malformations of the outer or middle ear, making a significant hearing loss highly likely.- Treacher Collins syndrome :...

), and dental problems are also common. Broad thumbs and toes are extra-cranial features of this syndrome.

Classification

Pfeiffer syndrome is divided into three subtypes.
  • Type 1 or "classic" Pfeiffer syndrome has symptoms as described above. Most individuals with type 1 have normal intelligence and a normal life span.
  • Types 2 and 3 are more severe forms of Pfeiffer syndrome, often involving problems with the nervous system. Type 2 is distinguished from type 3 by more extensive fusion of bones in the skull, leading to a "cloverleaf" shaped head.

External links

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