Syndromic (15% cases)
- Severity
- Mild cases
- No functional complications
- Management
- Conservative
- Surgical treatment
- Indication
- Cosmesis
- Defer definitive surgery until growth is complete
- Reducing pschological impact of deformity
- Severe cases
- Management
- Surgery
- indication
- Aim to preserve function by managing complication associated with
- Airway
- ICP
- Exorbitism
- Failure to thrive
- Cosmesis
- Defer definitive surgery until growth is complete
- Reducing psychological impact of deformity
- Associated tumour types
- Craniopharyngiomas (6-9%)
- Optic Pathway Hypothalamic Astrocytomas (2-7%)
- Germinomas (3%)
- Pituitary Adenomas (1-2%)
- Dermoids / Epidermoids
- Other:
- Meningiomas
- Haemangiomas
- Ependymomas
- Schwannomas
- Cavernomas
Phenotypic Features
Images
Genetic Mutations
Surgical indication
Muenke’s syndrome
- Unicoronal or bicoronal craniosynostosis
- Brachydactyly
- Thimble-like middle phalanges
- Coned epiphyses
- Carpal and tarsal fusions
- Sensorineural hearing loss
- Developmental delay
- Learning difficulties
- Seizures
- FGFR3
- Autosomal dominant.
- Caused by a point mutation in Pr0250Arg in the Ig 11-111 linker region of the FGFR3 gene on chromosome 4p16.3
Abnormal skull shape
Low risk of raised ICP
Low risk of raised ICP
Saethre-Chotzen syndrome
- Manifestations very variable → need genetic testing
- Coronal craniosynostosis with limb abnormalities (syndactyly of the second and third digits, bifid hallux)
- Facial abnormalities (facial asymmetry, low frontal hairline, ptosis, and small ears with prominent ear crura)
- TWIST1 Chr 7
- Autosomal dominant with complete penetrance and variable expressivity.
- Caused by loss-of-function mutations in TWIST (missense, nonsense, deletions, insertions, and duplications). Report of Q289P mutation in FGFR2
Abnormal skull shape Risk of ICP.
Crouzon’s syndrome
- Most common
- Classical triad
- Coronal synostosis
- Midfacial hypoplasia
- Exophthalmos
- Other features
- May also include involvement of other calvarial sutures
- Brachycephaly
- Hypertelorism
- Chiari I malformation
- Hydrocephalus
- Mental retardation
- FGFR2 Chr 10
- Autosomal dominant.
- Caused by numerous missense mutations in the Ig 111 domain of the FGFR2 gene (many involve the gain or loss of a cysteine residue)
Abnormal skull shape Risk of ICP.
Pfeiffer’s syndrome
- Classical features
- brachycephaly
- membranous syndactyly of hands and feet with enlarged and deviated thumbs and great toes
- Types
- Type I classical Pfeiffer’s syndrome is a mild entity
- Types II and III are more severe, with early death.
- Other features
- Coronal synostosis with or without premature fusion of other calvarial sutures
- Cloverleaf skull
- Facial
- maxillary hypoplasia
- small nose with a low nasal bridge
- hypertelorism
- shallow orbits
- proptosis
- strabismus
- limb malformation
- Radiohumeral synostosis
- Broad fingers and toes
- partial syndactyly of the fingers and toes
- FGFR1, FGFR2
- Type I: autosomal dominant.
- Caused by FGFR1mutations, including Pr0252Arg in the Ig II-III linker region on chromosome 8p11.2-p11.
- Can also be caused by mutations in FGFR2 and be associated with more severe phenotypic expression.
- Types II and III: sporadic inheritance.
Apert’s syndrome (Acrocephalosyndactyly)
- 2nd most common
- Features
- Bicoronal synostosis
- Severe polysyndactyly in the fingers and toes
- Symphalangism (fusion of the phalanges)
- Radiohumeral fusion
- Mental retardation (IQ can be normal or mildly reduced)
- Antimongoloid slanted eyes
- Maxillary hypoplasia
- Cheerful effect
- Vs Crouzon's at the faciocranial level
- is the presence of hypertelorism and an open bite, in which the anterior part of the maxillary alveolar arch is higher than the posterior part.
- The face and the forehead are also abnormally wide, and the anterior fontanelle is widely open during the first months of life.
- FGFR2
- Autosomal dominant.
- Caused by a number of different mutations in FGFR2 on chromosome 10q26, including two missense mutations (Ser252Trp, Pr0253Arg) and two Alu insertions
Abnormal skull shape Risk of ICP.
Jackson-Weiss syndrome
- Like Crouzon's but with added enlarged great toes and tarsometatarsic fusion.
- Craniosynostosis, with broad toes and a medially deviated great toe, second and third toe syndactyly, tarsal-metatarsal fusion, broad and short metatarsals and proximal phalanges, midfacial hypoplasia, hypertelorism, proptosis, and normal intelligence
- FGFR2
- Autosomal dominant.
- Caused by mutation A344G in the highly conserved Ig IIIc domain of FGFR2,as well as two nucleotide missense mutations that result in Cys342Ser and Cys342Arg