title: Kosaki overgrowth syndrome
text: # Kosaki overgrowth syndrome
  
  Kosaki overgrowth syndrome is a rare syndrome caused by mutations in the PDGFRB gene.
  
  ## Presentation
  
  The features of this syndrome affect the face, skin, brain and the body.
  
  Face:
  
  * downslanting palpebral fissures
  * pointed chin
  * prominent forehead
  * proptosis
  * thin upper lip
  * wide nasal bridge
  
  Skin:
  
  * fragile
  * hyperelastic
  
  Brain:
  
  * Low IQ
  * Periventricular white matter lesions
  
  Body:
  
  The height, lower-segment, hand, and foot length are all greater than usual.
  
  ## Genetics
  
  No inheritance pattern has been described as these mutations appear to have arisen de novo. This syndrome is due to mutations in a single copy of the PDGFRB gene.
  
  ## History
  
  This condition was first described in Japan in 2011 by Watanabe et al. These authors thought the condition was the Shprintzen-Goldberg syndrome but the patient lacked a mutation in the SKI gene. A second case was described by Takenouchi et al in 2015. These authors recognised that this condition was novel and on performing a whole genome sequencing found mutations in the PDGFRB gene. A further 24 cases were reported in 2017 by Gawliński et al.
  
  