Kosaki overgrowth syndrome
# 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.

