Recently mutations in fibroblast growth factor receptor 2 (FGFR2) have been found in patients with another craniosynostotic syndrome, Crouzon syndrome.
We have identified a novel missense mutation in the FGFR2 gene that predicts an Ala362Ser substitution shared by all family members affected by Crouzon syndrome and by a "clinically normal"-appearing father.
Using the published primers for PCR, a patient with Crouzon syndrome was found to be homozygous for a mutation that results in a Q289P amino acid substitution in FGFR2.
The Crouzon syndrome, which is associated with fibroblast growth factor receptor (FGFR2) mutations, is characterized by premature fusion of cranial sutures.
Genotype-phenotype analyses based on our cohort and previous studies further indicate that in spite of some overlap, PS and CS are preferentially accounted for by two distinct sets of FGFR2 mutations.
We measured the foramen magnum area (FMA) and its sagittal and transversal components: the right, left, and mean area of the jugular foramen; the posterior fossa volume; and the cerebellar volume on preoperative millimetric computed tomography scan slices in 31 children with an FGFR2 mutation (14 with Crouzon syndrome, 11 with Apert syndrome, and 6 with Pfeiffer syndrome).
Given that a mutation in codon 342 was found in 8 out of 17 cases and that in 9 cases the mutation occurred at five additional positions, codon 342 of exon B of the FGFR2 gene may be predisposed to mutations in Crouzon syndrome.
The association of non-dwarfing and even non-skeletal conditions with FGFR3 mutations reveals the potential for a wide range of FGFR pleiotropic effects as well as locus heterogeneity in Crouzon syndrome.
Acanthosis nigricans (AN) has been reported in association with severe skeletal dysplasias due to activating mutations in FGFR3, including thanatophoric dysplasia, severe achondroplasia (ACH) with developmental delay and AN (SADDAN syndrome), and Crouzon syndrome with AN.