Lévêque Marianne, Marlin Sandrine, Jonard Laurence, Procaccio Vincent, Reynier Pascal, Amati-Bonneau Patrizia, Baulande Sylvain, Pierron Denis, Lacombe Didier, Duriez Françoise, Francannet Christine, Mom Thierry, Journel Hubert, Catros Hélène, Drouin-Garraud Valérie, Obstoy Marie-Françoise, Dollfus Hélène, Eliot Marie-Madeleine, Faivre Laurence, Duvillard Christian, Couderc Remy, Garabedian Eréa-Noël, Petit Christine, Feldmann Delphine, Denoyelle Françoise
INSERM U587, Pasteur Institute, Paris, France.
Eur J Hum Genet. 2007 Nov;15(11):1145-55. doi: 10.1038/sj.ejhg.5201891. Epub 2007 Jul 18.
Mitochondrial DNA (mtDNA) mutations have been implicated in non-syndromic hearing loss either as primary or as predisposing factors. As only a part of the mitochondrial genome is usually explored in deafness, its prevalence is probably under-estimated. Among 1350 families with non-syndromic sensorineural hearing loss collected through a French collaborative network, we selected 29 large families with a clear maternal lineage and screened them for known mtDNA mutations in 12S rRNA, tRNASer(UCN) and tRNALeu(UUR) genes. When no mutation could be identified, a whole mitochondrial genome screening was performed, using a microarray resequencing chip: the MitoChip version 2.0 developed by Affymetrix Inc. Known mtDNA mutations was found in nine of the 29 families, which are described in the article: five with A1555G, two with the T7511C, one with 7472insC and one with A3243G mutation. In the remaining 20 families, the resequencing Mitochip detected 258 mitochondrial homoplasmic variants and 107 potentially heteroplasmic variants. Controls were made by direct sequencing on selected fragments and showed a high sensibility of the MitoChip but a low specificity, especially for heteroplasmic variations. An original analysis on the basis of species conservation, frequency and phylogenetic investigation was performed to select the more probably pathogenic variants. The entire genome analysis allowed us to identify five additional families with a putatively pathogenic mitochondrial variant: T669C, C1537T, G8078A, G12236A and G15077A. These results indicate that the new MitoChip platform is a rapid and valuable tool for identification of new mtDNA mutations in deafness.
线粒体DNA（mtDNA）突变已被认为是导致非综合征性听力损失的主要因素或易感因素。由于在耳聋研究中通常只探究线粒体基因组的一部分，其实际患病率可能被低估了。在通过法国合作网络收集的1350个非综合征性感音神经性听力损失家庭中，我们挑选出29个母系谱系明确的大家庭，并对其12S rRNA、tRNASer(UCN)和tRNALeu(UUR)基因中的已知mtDNA突变进行筛查。当未发现突变时，使用微阵列重测序芯片（Affymetrix公司开发的MitoChip 2.0版）进行全线粒体基因组筛查。在这29个家庭中的9个家庭中发现了已知的mtDNA突变，本文对此进行了描述：5个家庭存在A1555G突变，2个家庭存在T7511C突变，1个家庭存在7472insC突变，1个家庭存在A3243G突变。在其余20个家庭中，重测序的Mitochip检测到258个线粒体纯合变异和107个潜在的杂合变异。通过对选定片段进行直接测序进行对照，结果显示MitoChip具有较高的灵敏度，但特异性较低，尤其是对于杂合变异。基于物种保守性、频率和系统发育研究进行了一项原创性分析，以选择更可能具有致病性的变异。全基因组分析使我们能够识别出另外5个具有假定致病性线粒体变异的家庭：T669C、C1537T、G8078A、G12236A和G15077A。这些结果表明，新的MitoChip平台是一种快速且有价值的工具，可用于识别耳聋中的新mtDNA突变。
