Jackson-Weiss is a syndrome marked by the early fusion of cranial sutures (known as craniosynostosis) and growth abnormalities of the feet.


People born with Jackson-Weiss syndrome develop enlarged big toes that medially deviate (skew toward the center of the body) from the rest of the foot. They also suffer from premature fusion of the cranial sutures. Normally, the cranial sutures of infants remain unfused, to allow for growth. With craniosynostosis, there is an increase of intercranial pressure and the expansion of the skull leads to a protruding forehead, bulging, widely-spaced eyes, and a misshapen skull.

Early Warning Signs

  • Lack of fontanelle (soft spot) on a newborn's head.
  • Early disappearance of the fontanelle.
  • Hard bone ridges along the cranial sutures.
  • No increase in head size as the child matures.

Genetic Basis

Jackson-Weiss results from a mutation in the gene that produces fibroblast growth factor receptor 2, appropriately named FGFR2. This protein is responsible for signalling immature cells to become bone cells. The syndrome is autosomal dominant, which means that only one mutated gene need be present to cause the protein anomaly. The risk of a person with Jackson-Weiss passing the mutation to their child is 50%.


Cranial surgery to increase the size of the cranial vault, as early as three months, followed by cosmetic surgery to normalize the features.


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