Center for Human Genetics and Laboratory Diagnostics, Dr. Klein, Dr. Rost and Colleagues

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Pfeiffer Syndrome [Q75.0]

OMIM numbers: 101600, 136350 (FGFR1), 176943 (FGFR2)

Dr. med. Imma Rost, Dipl.-Biol. Christina Sofeso

Scientific Background

The Pfeiffer syndrome (acrocephalosyndactyly syndrome type 5, ACS5) belongs to the group of craniosynostosis. There are 3 different clinical types of Pfeiffer syndrome:

  • Type 1 (classical Pfeiffer syndrome): Synostosis usually affects the coronary suture with brachycephaly, mid-face hypoplasia, hypertelorism, exophthalmos and mandibular prognathism. Broad thumbs and big toes with radial or tibial deviation as well as sometimes proximal cutaneous syndactyly are characteristic. Intelligence is usually unimpaired.
  • Type 2: Clover leaf skull as well as hand and foot malformations similar to type 1 are characteristic.
  • Type 3: Phenotype similar to type 2; no clover leaf skull.

Type 1 is usually familial with complete penetrance and varying severity; type 2 and 3 are more common than type 1 and always occur sporadically. The patients are generally affected more severely than in type 1; life expectancy is reduced significantly. The exact frequency of the Pfeiffer syndrome is not known; however, it is considerably rarer than the Apert or Crouzon syndrome. The Pfeiffer syndrome is caused by mutations in the FGFR1 and FGFR2 gene. The types 2 and 3 are always caused by mutations in the FGFR2 gene, type 1 in 95% of all cases.