中国人LHON患者mtDNA继发突变的筛查

Screen the secondary nutations of mtDNA in Chinese patients with LHON

目的 分析中国人Leber遗传性视神经病变(Leber’s hereditary optic neuropathy,LHON)线粒体DNA 4个继发突变 位点与LHON发病的关系。方法 分别用突变特异性引物聚合酶链反应,异源双链-单链构象多态性,限制性片段长度多态 性和DNA测序方法,对137例LHON患者、60例不明原因球后视神经炎进行mtDNA3394C、9438A、13708A、4216C 4个继发位点 的检测,并以100例正常人作对照。结果 在4例LHON患者(包括3例11778突变、1例3460突变)、2例不明原因球后视神经 炎患者及1例正常人中发现存在13708位点突变(G-A),引起ND5蛋白第458住中度保守丙氨酸变成苏氨酸(A458T)。经X2 检验,无统计学意义。在1例正常人中检测到3394位点T→C突变,造成ND1蛋白第30位高度保守酪氨酸变成组氨酸 (Y30H)。137例LHON患者及60例不明原因球后视神经炎患者均未发现此位点突变。在137例LHON患者、60例不明原因球 后视神经炎患者及100倒正常人中未检测到9438及4216位点突变。结论 我们的研究结果与日本、韩国研究结果相似,初步 排除了在中国人Leber遗传性视神经病变患者中13708A、3394C、9438A、4216C四种突变协同原发突变发病的可能性。

Objective：To screen the secondary mutations of LHON in Chinese patients, and to find the probable relationship between the secondary mutations and the incomplete penetrance of LHON. Methods： Genomic DNA was collected from 137 LHON patients, 60 retrobulbar neuritis of unknown etiology patients and 100 normal healthy persons. The mltochedrial DNA mutations at nucleotide position （np） 13708, 3394, 9438, and 4216 are screened by using pelymerase chain reaction （PCR）, heteroduplex - single strand conformation pelymorphism pelymrase chain Reaction （HA - SSCP） and restriction fragment length pelymorphism （RFLP） analysis and sequencing. Results： Four LHON patients, including three patients with the 11778 mutation, one with 3460 mutation, two retrobulbar neuritis of unknown etiology patients and 1 normal healthy person have an np 13708A mutation, with change of amino acid sequence of protein ND6 （A458T）. There is no statistics difference. One normal healthy person had an np 3394 mutation, with change of amino acid sequence of protein ND1 （Y30H）. 137 LHON patients, 60 retrobulbar neuritis of unknown etiology patients didn＇ t habour the mutation. None of LHON patients, retrobulbar neuritis of unknown etiology patients and normal healthy persons habour the mutation at np 9438, 4216. Conclusion：There was no evidence that mtDNA mutation at np 13708A, 3394C, 9438A, 4216C had synergistic effect on the expression of LHON.