What is Pfeiffer syndrome?
Pfeiffer syndrome is a rare genetic syndrome. It includes the premature fusion of specific skull bones, as well as thumb anomalies and anomalies affecting the large toes. Other main features include protruding eyes and hearing loss. There are currently 3 main types of the syndrome that have been identified. They vary in their causes and the exact specific symptoms associated with them.
This syndrome is also known as:
Acrocephalosyndactyly – type V; Acrocephalosyndactyly type V; Acrocephalosyndactyly, Type V; ACS5 ACS V; ACSV; Noack Syndrome
What gene changes cause Pfeiffer syndrome?
- Type 1 is caused by changes in the FGFR1 and FGFR2 gene.
- Types 2 and 3 are caused by changes in the FGFR2 gene.
The syndrome is inherited in an autosomal dominant pattern. In the case of autosomal dominant inheritance just one parent is the carrier of the gene mutation, and they have a 50% chance of passing it onto each of their children. Syndromes inherited in an autosomal dominant inheritance are caused by just one copy of the gene mutation.
What are the main symptoms of Pfeiffer syndrome?
The main symptoms may vary according to the type of the syndrome individuals are affected by.
- Type 1: the main symptoms are a prominent forehead, widely spaced eyes, underdeveloped upper jaw, prominent lower jaw, and dental abnormalities. The syndrome usually does not impact intellectual ability and development.
- Type 2: the symptoms with this type of the syndrome are considered more severe. Individuals have what is known as a cloverleaf skull which can also lead to an increase of fluid in the skull and a subsequent increase of pressure on the brain. This type of syndrome also affects neurodevelopment and usually presents with intellectual disability and developmental delay. Health issues associated with this type of syndrome can be serious if not treated properly and promptly during infancy.
- Type 3: this presents with similar symptoms as Type 2, but without the cloverleaf skull. Other features of this form of the syndrome include a shorter skull base, babies born with teeth, protrusion of the eyes, and anomalies of internal abdominal organs. Intellectual disability is a defining feature of this form of the syndrome as well.
Possible clinical traits/features:
Short middle phalanx of toe, Ptosis, Strabismus, Short philtrum, Synostosis of carpal bones, Symphalangism affecting the phalanges of the hand, Shortening of all middle phalanges of the fingers, Brachydactyly, Coronal craniosynostosis, Elbow ankylosis, Cloverleaf skull, Clinodactyly of the 5th finger, Facial asymmetry, Finger syndactyly, Dental crowding, Malar flattening, Downslanted palpebral fissures, Intellectual disability, Short nose, Mandibular prognathia, Hypoplasia of the maxilla, Hypoplasia of the zygomatic bone, High forehead, High palate, Hydrocephalus, Humeroradial synostosis, Hypertelorism, Hyperlordosis, Depressed nasal bridge, Short stature, Autosomal dominant inheritance, Open mouth, Shallow orbits, Short neck, Abnormality of the hip bone, Bronchomalacia, Broad hallux, Broad thumb, Cartilaginous trachea, Brachyturricephaly, Wide nasal bridge, Arnold-Chiari malformation, Abnormality of thumb phalanx, Abnormal palate morphology, Choanal stenosis, Choanal atresia.
How is it diagnosed?
To find out if someone has a diagnosis of Pfeiffer syndrome, it is important to have a consultation and evaluation with a clinical genetic specialist. Specialists may also suggest specific genetic testing or other types of tests to help reach a diagnosis. FDNA’s AI technology can help speed up the diagnostic process by analyzing facial features and other health information.
