散发型甲状腺髓样癌酪氨酸激酶受体基因第918位点基因突变及意义

目的研究不同人种散发型甲状腺髓样癌（sMTC）酪氨酸激酶受体基因（RET）第918位点基因突变及意义。方法提取17例中国人sMTC基因组DNA，聚合酶链反应（PCR）扩增RET基因第16外显子，PCR产物经纯化后直接测序，分析中国人sMTCRET基因第918位点处基因突变，并与文献报道的其他人种sMTC该位点处基因突变比较。结果中国人sMTC此位点处未发现基因突变；黄种人、白种人、棕种人此位点处基因突变率分别为：7．1％、33．5％、50．0％。基因突变形式均为ATG→ACG点突变。白种人与黄种人，棕种人与黄种人间比较均差异有统计学意义（P〈0．05）。结论中国人sMTC发病与RET基因第918位点处基因突变无关；不同人种sMTC此位点处基因突变率有差异；不同人种sMTC发病的基因基础可能不同。

Experimental study on the mutation rate of exon 16-codon 918 from RET proto-oncogene in different human races with sporadic medullary thyroid carcinoma

To investigate the mutation of exon 16 codon 918 from RET proto-oncogene in Chinese sporadic medullary thyroid carcinoma and compare the mutation rate in this codon in different human races. Methods Genomic DNA was extracted from 17 Chinese patients with sporadic MTC.Exon 16 of RET proto-oncogene was amplified by polymerase chain reaction (PCR), analyzed by automated DNA sequencer and compared with Genebank. Results No gene mutation was detected in exon 16 of RET proto-oncogene in Chinese sporadic MTC. According to the related literatures, the mutation rate in codon 918 of exon 16 in yellow race, white people and brown was 7.1 %, 33.5 % and 50.0 %, respectively. There was significant difference in the mutation rate between white and yellow race and between brown and yellow race (P<0.05).Conclusion The mutation of RET proto-oncogene codon 918 in exon 16 is not the key mutation in Chinese sporadic MTC. There is significant difference in mutation rate at codon 918 in different human races. The gene basis of sporadic MTC episode in different human races may be various.