应用变性高效液相色谱技术检测结节性硬化症TSC1基因外显子15基因突变的研究

Study of TSC1 gene exon 15 mutation detected by denaturing high performance liquid chromatography in Chinese patients with tuberous sclerosis complex

目的探讨结节性硬化症(TSC)TSC1基因外显子15基因突变的特点。方法 1996—2006年采用多聚酶链扩增和变性高效液相色谱(DHPLC)技术,对21个家系59名研究对象进行了TSC1基因外显子15检测,对DHPLC检测异常者再进行多聚酶链扩增产物直接测序方法证实其突变类型。结果对21个家系TSC1基因外显子15共检测出4个家系的3种突变形式,其中c.1708～1709delAG(p.Arg570GlyfsX17)与c.1888～1891delAAAG(p.Lys630GlnfsX22)两种突变为国内尚未报道的小的缺失突变,c.1460C>G(p.Ser487Cys)突变为1种罕见的错义突变。TSC1基因外显子15突变基因检出频率为4/21(19%)。在检出突变的4个家系中1个为家系突变,其余3个为散发突变。结论 TSC1基因外显子15的c.1460C>G(p.Ser487Cys),c.1708～1709delAG(p.Arg570GlyfsX17)与c.1888～1891delAAAG(p.Lys630GlnfsX22)突变为目前国内首报突变。

Objective To study the characteristics of mutation of TSC1 gene exaM 15 in tuberous sclerosis complex. Methods Totally 21 children with confirmed clinical manifestations of TSC and 38 parents of the children coming from 21 TSC families were included in the study. In total, we studied 6 familial cases and 15 sporadic cases. The mutation of exon 15 in TSC1 gene was identified by denaturing high performance liquid chromatography （DHPLC） and further confirmed by direct sequencing. Results After being confirmed by DNA direct sequencing, mutations were identified in 4/21 （19%）patients, in which there were c.1708-1709delAG （p.Arg570GlyfsX17） and c.1888-1891delAAAG （p. Lys630GlnfsX22） two small deletion mutations and one c.1460C 〉 G（p.Ser487Cys） missense mutation, c.1460C 〉 G（p. Ser487Cys） mutation was reported the second. One family case and three sporadic cases were found. In our study, the mutation frequency of exon 15 in TSC1 gene was 4/21 （ 19% ）, which was higher than other reports. The main clinical characters of the patients with mutation on exon 15 in TSC1 gene were brain and skin impair. We also found that the patients with the same mutation c.1888-1891delAAAG （p.Lys630GlnfsX22） had different phenotype, but the patients with different mutations c.1708-1709delAG （p.Arg570GlyfsX17） and c.1888-1891delAAAG （p.Lys630GlnfsX22） nearly had the same phenotype. Conclusion Totally three TSC1 gene mutations that have never been reported in China are identified.