Main page/Syndromic craniosynothosis

Syndromic craniosynothosis

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
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  • 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
 

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)
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  • 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
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  • 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
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  • 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.
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  • 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