Novel SNP at the common primer site of exon IIIa of FGFR2 gene causes error in molecular diagnosis of craniosynostosis syndrome.
Novel SNP at the common primer site of exon IIIa of FGFR2 gene causes error in molecular diagnosis of craniosynostosis syndrome.
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DOI：
10.1002/ajmg.1461
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发表时间：
2001-08
期刊：
影响因子：
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通讯作者：
L. Wong;T. J. Chen;P. Dai;L. Bird;M. Muenke
中科院分区：
文献类型：
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作者：
L. Wong;T. J. Chen;P. Dai;L. Bird;M. Muenke
Crouzon、Pfeiffer 和 Apert 综合征中的大多数突变位于成纤维细胞生长因子受体 2 (FGFR2) 基因的细胞外、第三免疫球蛋白样结构域和相邻接头区域（外显子 IIIa 和 IIIc）。使用已发表的 PCR 引物，发现一名克鲁松综合征患者具有导致 FGFR2 中 Q289P 氨基酸取代的突变纯合子。另外两名患者；一名患有阿佩尔综合征和 P253R 突变，另一名患有普法伊弗综合征和 S267P 突变，也似乎是纯合子。使用位于外显子 IIIa 5' 146 bp 的新引物进行 PCR，随后测序显示外显子 IIIa 的 -62 [校正] 位置存在 A 至 G 多态性。所有三名患者的突变和多态性都是杂合的。这些结果表明多态性和突变不在同一染色体上。单核苷酸多态性位于已发表引物3'端倒数第二个碱基处。这种引物错配导致正常染色体扩增失败，从而导致明显的纯合性。通过研究普通人群的 326 条染色体，确定这种新型多态性的频率为 0.03。我们建议使用新的引物对FGFR2外显子IIIa进行突变分析，以避免引物不匹配造成的误诊。
Most mutations in Crouzon, Pfeiffer, and Apert syndromes are in the extracellular, third immunoglobulin-like domain and adjacent linker regions (exons IIIa and IIIc) of the fibroblast growth factor receptor 2 (FGFR2) gene. 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. Two additional patients; one with Apert syndrome and P253R mutation, the other with Pfeiffer syndrome and S267P mutation, also appeared to be homozygous. Using a new primer located 146 bp 5' of exon IIIa for PCR followed by sequencing revealed an A to G polymorphism at -62 [corrected] position of exon IIIa. All three patients were heterozygous for both the mutation and the polymorphism. These results indicate that the polymorphism and the mutation are not on the same chromosome. The single nucleotide polymorphism is located at the second to the last base of the 3' end of the published primer. This primer mismatch caused the failure of amplification of the normal chromosome and thus, the apparent homozygosity. The frequency of this novel polymorphism was determined to be 0.03 by studying 326 chromosomes from the general population. We propose that a new primer should be used for mutational analysis of exon IIIa of FGFR2 to avoid misdiagnosis caused by primer mismatch.