Schematic representation of the primers from the humanFGFR3 gene used in the study. The FGFR3 exons are indicated by white boxes, and the introns are indicated by lines. The 3′ untranslated region is indicated by the dashed box. The approximate locations of the primers, the length of the amplified fragments, and the approximate positions of codons 248, 540, 650, and 807 are indicated. The nucleotide sequence of FGFR3 cDNA and the intron-exon organization of the gene have been previously reported.12,13 The sequences of the primers are as follows: 248F (intron 6), 5′-CCTGAGCGTCATCTGCC-3′, and 248R (exon 7), 5′-CCATTGCATCCCACACGG-3′; TD5 (exon 10), 5′-AGGAGCTGGTGGAGGCTGA-3′, and TD3 (exon 10), 5′-GGAGATCTTGTGCACGGTGG-3′¹⁴; 540F (exon 13), 5′-ACTGACAAGGACCTGTCGGAC-3′, and 540R (exon 13), 5′-GCCCTGCGTGCAGGCGCC-3′; 650F (exon 15), 5′-GCATCCACAGGGACCTGG-3′, and 650R (intron 15), 5′-AGGCGGTGTTGGCGCCAG-3′; 14S (exon 15), 5′-GTGCACAACCTCGACTAC-3′ (this primer was used with 650R to obtain a DNA fragment suitable for the restriction enzyme analysis of codon 650); 807F (exon 19), 5′-CCTGTCGGCGCCTTTCGAGCAGTAC-3′, and 807R (exon 19), 5′-CACCAGCAGCAGGGTGGGCTGCTAG-3′.15