INTRODUCTION The purpose of this study was to investigate the correlation between sperm mitochondrial NADH dehydrogenase subunit 5 (ND5) and NADH dehydrogenase subunit 6 (ND6) gene variations and total fertilisation failure (TFF). MATERIAL AND METHODS A total of 232 sperm samples at the fresh in vitro fertilisation (IVF) cycle or the half-intracytoplasmic sperm injection (ICSI) cycle were collected for this retrospective controlled study on Han Chinese people between July 2011 and April 2014. Of the 232 total samples, 45 were from the IVF-TFF group and 187 were from couples with normal fertilisation (fertilisation rate > 50%). The mitochondrial ND5 and ND6 gene variations and sperm haplotypes were confirmed using nested PCR and DNA sequencing. RESULTS Ten homozygous variations were newly discovered, namely C12417T, T12441A, C12543A, C13650A, C13765A, T13769C, C13775T, A13776G, C13785A and C13845T. The gene variation rates of six sites, C12417T, C13650A, C13765A, T13769C, C13785A and C13845T, in the TFF group were significantly higher than those in the control group (p < 0.05). There were 231 heterozygous variations discovered; however, only nine heterozygous sites (12441, 12561, 12735, 13164, 13743, 13812, 13928, 14172 and 14368) had significantly higher gene variation rates than those in the control group (p < 0.05). In addition, the results showed that haplogroup C did not affect TFF (p > 0.05), and the fertilisation failure rates of haplogroup R and haplogroup D4a were both higher than those in the control group (p < 0.05). CONCLUSIONS Our results suggested that the ND5 and ND6 gene variations are correlated with TFF. Furthermore, this study indicated that haplogroup R and haplogroup D4a might be risk factors for TFF.

中文翻译：

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精子线粒体 ND5 和 ND6 基因变异与总受精失败的相关性。

引言 本研究的目的是调查精子线粒体 NADH 脱氢酶亚基 5 (ND5) 和 NADH 脱氢酶亚基 6 (ND6) 基因变异与总受精失败 (TFF) 之间的相关性。材料与方法 2011 年 7 月至 2014 年 4 月对汉族人进行回顾性对照研究，共收集新鲜体外受精（IVF）周期或半胞浆内单精子注射（ICSI）周期的精子样本 232 份。总共232个样本，45个来自IVF-TFF组，187个来自正常受精的夫妇（受精率> 50％）。使用巢式 PCR 和 DNA 测序确认线粒体 ND5 和 ND6 基因变异和精子单倍型。结果 新发现10个纯合变异体，分别为C12417T、T12441A、C12543A、C13650A、C13765A、T13769C、C13775T、A13776G、C13785A 和 C13845T。TFF组C12417T、C13650A、C13765A、T13769C、C13785A和C13845T六个位点的基因变异率显着高于对照组（p < 0.05）。共发现231个杂合变异；然而，只有 9 个杂合位点（12441、12561、12735、13164、13743、13812、13928、14172 和 14368）的基因变异率显着高于对照组（p < 0.05）。此外，结果显示单倍群C不影响TFF（p>0.05），单倍群R和单倍群D4a的受精失败率均高于对照组（p<0.05）。结论 我们的结果表明 ND5 和 ND6 基因变异与 TFF 相关。此外，