HUMAN MUTATION Supplement 1:S18-S19 (1998)

MUTATION IN BFUEF

Two Common Mutations 934C to G and 937C to G of Fibroblast 6rowth Factor Receptor 2 (FGFR2) Gene in Chinese Patients th Apert Syndrome Fuu-]en Tsai,'" Wuh-Liang Hwu,' Shuan-Pei Lin,3 Jan-Gowth Chans4 Tso-Ren Wang2 and Chang-Hai Tsai' 'Department of Pediatrics, China Medical College Hospital, Taichung, Taipei, Taiwan 2Department of Pediatrics and Medical Genetics, National Taiwan University Hospital, Taipei, Taiwan 3Department of Pediatrics, Mackay Memorial Hospital, Taipei, Taiwan 4Department of Molecular Medicine, Tapei Municipal Jen-Ai Hospital, Taipei, Taiwan

Communicated by Garry R. Cutting

Apert syndrome is a clinically distinct condition characterized by craniosynostosis, craniofacial anomalies, and symmetric syndactyly of the digits (Cohen and Kreiborg, 1986). Recently, a fibroblast growth factor receptor (FGFR2) mutation, either 934C to G or 937C to G, was found in exon 111 a (Wilkie et al., 1995a). To see if these mutations were also prevalent in Chinese patients, this report dis- cusses cases of Apert syndrome examined by both restriction analysis and direct sequencing.

Genomic DNA was isolated from leukocytes of seven unrelated cases of Apert syndrome, parents of the patients, and 10 normal controls. The diagnosis of Apert syndrome was made according to typical craniofacial features and symmetric syndactyly. PCR from genomic DNA was performed by the method of Wilkie et al. (199510). A specific fragment of FGFR2 carrying the mutation was amplified followed by diges- tion with SfiI and BstUI. One-third of the product from a 100 p1 PCR reaction was purified and digested with 2 U of SfiI and BstUI, then eletrophoresed on a 3.5% agarose gel (FMC bioproducts). Direct automatic se- quencing was performed with an Applied Biosystems 3 77 DNA sequencer according to the manufacturer's instructions.

Of the seven unrelated patients studied, 6 (83.3%) had the 934C to G (Ser 252 Trp) muta- tion and 1 (16.7%) had the 937C to G (Pro 253 Arg) mutation (Fig. 1). PCR products from all seven cases of Apert syndrome were cleaved by SfiI or BstUI (all were heterozygote). In contrast, DNA from either patients of Apert syndrome or normal controls could not be cleaved. Direct se-

quencing of DNA of all Apert syndrome patients showed the presence of both C and G at position 934 or 937 (data not shown). These results dem- onstrated that all Apert syndrome patients tested in this study have the similar mutation as previ- ously reported; therefore there may be no racial difference.

To date, only one patient with Apert syndrome is without one of these two mutations (Park et al., 1995), and this patient does not have a FGFR2 mutation in this critical region. These two muta- tions in Apert syndrome replace adjacent neutral amino acids with amino acids with larger side chains, and the 937C to G mutation introduces a basic side chain. The other rare mutations for Apert syndrome may be identified either in the same functional region in other FGFRs or other functional regions of FGFR2 that have similar bio- chemical consequences (Park et al., 1995). A study of the biochemical function of these mutant FGFRs in tissue culture or transgenic animal sys- tems will be necessary to understand the patho- genesis of these disorder.

Received 12 December 1995; accepted 5 March 1996. *Correspondence to: Fuu-Jen Tsai, Department of Pediatrics,

China Medical College Hospital, Taichung, Taipei, Taiwan. Fax: 886- 4-2032798.

0 1998 WILEY-LISS. INC.

FGFFtP GENE MUTATIONS S19

FIGURE 1. Detection of the 934C to G mutation (A) and 937C to G mutation (B) by Sfil and BstUl restriction analysis. Fragment lengths are given in base pairs (bp). The lane M; DNA ladder (2,000, 1,500, 1.000, 700, 500,400,300,200, 100, and 50 bp; Amersham), Lane 1 of gel A and B; normal control, Lane 2(A); Apert syndrome with 934 C to G muta- tion, Lane 2(B); Apert syndrome with 937C to G mutation, Lane 3 (A and B); parents of Apert syndrome. The mutated base (under line) at nucleotide position 934 creates a Sfi re- striction site: GGCCNNNN I NCCGG.

REFERENCES Cohen MM ]r, Kreiborg S (1991) Genetic and family study of the

Apert syndrome. J Craniofac Genet Dev Biol 11:7-17. Park WJ, Theda C, Maestri NE, Meyers GA, Fryburg IS, Dufresne C,

Cohen MM Jr, Jabs EW (1995) Analysis of phenotypic features and FGFR2 mutations in Apert syndrome. Am J Hum Genet 57:321-328.

Wilkie AOM, Slaney SF, Oldridge M, Poole MD, Ashworth GJ, Hockley AD, Hayward RD, David DJ, Pulleyn LJ, Rutland Malcolm S, Winter RM, Reardon W (1995a) Apert syndrome results from localized mutations of FGFR2 and is allelic with Crouzon syndrome. Nat Genet 9: 165-172.

Wilkie AOM, Slaney SF, Oldridage M, Hurst JA, Poole MD (1995b) Apert syndrome: phenotype-genotype correlation for the two common mutations in FGFRZ. Am J Hum Genet 57 (supp):A139.