Crouzon syndrome / Pfeiffer syndrome

Characteristic findings are:

Various types of synostosis possible

Hypertelorism

Exorbitism

Midface hypoplasia

Crouzon and Pfeiffer syndrome have the same genetic background, although Pfeiffer is often used for the more severe presentation.

Caused by several types of mutations in FGFR2 and seldom in FGFR1. If combined with the skin disorder acanthosis nigricans, the genetic defect is found in FGFR3