Fibroblast growth factor receptor 2 (FGFR2): genomic sequence and variations

Abstract

Fibroblast growth factor receptors (FGFRs) play an important role in development and tumorigenesis. Mutations in FGFR2 cause more than five craniosynostosis syndromes. The FGFR2 genomic structure is the largest of the FGFR family. We have refined and extended the genomic organization of the FGFR2 gene by sequencing more than 119 kb of PACs, cosmids, and PCR products and assembling a region of approximately 175 kb. Although the gene structure has been reported to include only 20 exons, we have verified the presence of at least 22 exons, some of which are alternatively spliced. The sizes of six exons differed from those reported previously. Comparison of our sequence and those in the NCBI database detected more than 300 potential single nucleotide polymorphisms (SNPs). However, sequencing regions containing 52 of these potential SNPs verified only 14 in PCR products generated from 16 CEPH alleles. In contrast, direct sequencing of the CEPH DNAs revealed 21 other polymorphisms. Only one SNP was found in the 2,926 bp of coding sequence. Twenty-seven SNPs, two insertion polymorphisms and five microsatellite polymorphisms are contained in approximately 16.6 kb of non-coding sequence. These data yield an average of one polymorphism for approximately 488 bp of non-coding sequence examined. This collection of SNP, insertion, and repeat polymorphisms will aid future association studies between the FGFR2 gene and human disease and will enhance mutation detection.